With all the hiring going on, I doubt there is any reason to say "yes" if you do not intend to go. It could also buy you a problem.
If you check "yes", you might get a call from HR asking "we are interviewing for an FDA class. Are you interested?" When you say "well...no...thanks...things have changed" you might just go back into the standard stack. Then again, you might go into a "said he would but then backed out--do not call" stack. I think if you say "no" on that box you'll still get a call eventually, and likely will be hired. If they call you and you "change your mind" on the phone, I am not sure they will call you back.
We had an issue in 2011 with guys who applied saying they had an FE written but did not--they were going to get them in the next month. When HR saw the dates didn't line up, some were not offered the job. I think you can make a case "things changed..." That said, if HR perceives you were trying to manipulate them its really easy to just overlook you from then on. I don't think you need to take that risk.
Management will do what management will do. I suggest you do not make ethical decisions based on what others here tell you about management's ethics. People in management will change, leadership changes, and situations may change... Make the choice you feel is right, and let the chips fall. I suspect you will be successful and not have any drama if you take that course.
Standard disclaimer--I may be wrong...