How about this one?

   "What do you call the number of times that one number can be divided by another?" A) Dividend, B) Divisor, C) Quotient.

And a minor UX nitpick: please wrap the input element inside of a <label> tag, it makes it much easier to interact with form elements (in that I can click on the text to mark the element):

      <label class="answer">
        <input type="radio" name="q4" value="wrong" /> Condensation
      </label>