Draw four lines off from the beginning and from each of those lines draw another four lines and then from those lines draw 4 lines from each. There should be 4^3 = 64 total outcomes.

Normally you'd just fill in what you need to know though. For example if you want to know the chance of answer A being right twice and B being right the second one then you could do two branches,AandNot Awhere P(A') = 1-P(A) assuming the outcomes are mutually exclusive