Challenge with a mulitple respsonse question

Not sure if this should be posted here or one of the other forums, so sorry if this is the wrong one.

I have created a multiple response question, very simple, with two correct answers.  When i look at the question in slide view or form view, the two correct answers are identified.  When I go to preview the question and click on the correct answers, I consistently get the "incorrect" feedback. 

Currently options B and C are correct, option A is the only incorrect.  but when I preview it thinks option A and C are correct. 

Any ideas why this is occurring?

Thanks