How to check in a Rules Condition if a specific value of a multi-value field is selected? I have a "checkboxes" field that allows the user to select unlimited options. 
How do I check if at least a specific value has been selected?

I am using the Rules module, and when it checks if the 'field has value' it combines all the options. Right now, if both the values "b" AND "c" are selected, then the action (which checks for the value "b") won't be executed.
I ended up creating a "Check a Truth Value" condition with the Rules module. The code below is the one I used. 

if ($node-&gt;field_area_51[0]['value']) {
  foreach ($node-&gt;field_area_51 as $key =&gt; $value) {
    if ($value[value] == 'b') {
      return TRUE;
    }
  }
}