title: AngularJs: tooltip on mouse hover to single value of dropdown using ng-options
body: <p>I am using ng-options for dropdown using 'select' tag.
  I have to select only one option from drop down at a time.
  While selecting option from drop down I have to show tooltip when I am hovering mouse on particular option.
  I am able to show all the values in dropdown but not able to show the tooltip.</p>
  
  <p>Could anyone please tell me how to show tooltip for ng-options?</p>
  
  <p>Thanks</p>