You are right. The key must be wrong. Option B doesn't make sense.
Option A does make sense, as you correctly guessed. If you 'give something a miss', this means that you decide not to attend.
There is another slight problem with this question, though. Option C cannot be completely ruled out. If you 'give something a chance', it means that you try it out. I don't think it is the best answer here, but it isn't completely wrong either.
Another bad question, I'm afraid. The world is full of people who don't realise how hard it is to write decent multiple choice questions.