 
     it 'should display the X-axis dropdown items', ->
       page.xAxisDropdowns.then (dropdowns) ->
+        # The X-axis dropdown for the first chart.
         dropdown = _.first(dropdowns)
-        # Show the dropdown.
-        dropdown.click()
-        # The default selection for the first chart is 'RCB Index'.
+        # The default selection is 'RCB Index'.
         dropdown.find(By.css('.qi-dropbtn-label')).then (selected) ->
           expect(selected.text(), 'The default X-axis selection is incorrect')
             .to.eventually.equal('RCB Index')
-        # The first item in the dropdown is 'FXL Ktrans'.
-        dropdown.findAll(By.css('.qi-dropdown-item')).then (items) ->
-          item = _.first(items)
-          item.find(By.css('.qi-dropdown-label')).then (label) ->
-            expect(label.text(), 'The first item in the X-axis dropdown is' +
-                                 ' incorrect')
-              .to.eventually.equal('FXL Ktrans')
+        # Display the dropdown list.
+        dropdown.click().then ->
+          # The first item in the list is 'FXL Ktrans'.
+          dropdown.findAll(By.css('.qi-dropdown-item')).then (items) ->
+            item = _.first(items)
+            item.find(By.css('.qi-dropdown-label')).then (label) ->
+              expect(label.text(), 'The first item in the X-axis dropdown is' +
+                                   ' incorrect')
+                .to.eventually.equal('FXL Ktrans')
+              label.click().then ->
+                # The selected item changes to 'FXL Ktrans'.
+                dropdown.find(By.css('.qi-dropbtn-label')).then (selected) ->
+                  expect(selected.text(), 'The new X-axis selection is' +
+                                          ' incorrect')
+                    .to.eventually.equal('FXL Ktrans')
 
     it 'should display four Y-axis dropdowns', ->
       page.yAxisDropdowns.then (dropdowns) ->

      page.subjectTableGroups.then (subjects) ->
        subj = _.first(subjects)
        expect(subj.text(), 'The chart table does not display a' +
                                   ' subject')
          .to.eventually.include('Patient')

    it 'should display a session', ->
      page.subjectTableColumns.then (sessions) ->
        sess = _.first(sessions)
        expect(sess.text(), 'The chart table does not display a ' +
                                   ' session')
          .to.eventually.include('Visit')

    it 'should display the subject chart', ->


    it 'should display the Y-axis dropdown items', ->
      page.yAxisDropdowns.then (dropdowns) ->
        # The Y-axis dropdown for the first chart.
        dropdown = _.first(dropdowns)
        # The default selection is 'delta Ktrans'.
        dropdown.find(By.css('.qi-dropbtn-label')).then (selected) ->
          expect(selected.text(), 'The default Y-axis selection is incorrect')
            .to.eventually.equal('delta Ktrans')
        # Display the dropdown list.
        dropdown.click().then ->
          # The first item in the list is 'FXL Ktrans'.
          dropdown.findAll(By.css('.qi-dropdown-item')).then (items) ->
            item = _.first(items)
            item.find(By.css('.qi-dropdown-label')).then (label) ->
              expect(label.text(), 'The first item in the Y-axis dropdown is' +
                                   ' incorrect')
                .to.eventually.equal('FXL Ktrans')
              label.click().then ->
                # The selected item changes to 'FXL Ktrans'.
                dropdown.find(By.css('.qi-dropbtn-label')).then (selected) ->
                  expect(selected.text(), 'The new Y-axis selection is' +
                                          ' incorrect')
                    .to.eventually.equal('FXL Ktrans')
            # Categorical data types (e.g., TNM stage) are not permitted on the
            # Y-axis.
            for item in items
              item.find(By.css('.qi-dropdown-label')).then (label) ->
                expect(label.text(), 'TNM stage appears in the Y-axis' +
                                     ' dropdown')
                  .to.eventually.not.equal('TNM Stage')
