Answer- 1/12
Explanation- You can spin A,B,C,D, and you can roll 1,2,3,4,5, or 6.
Because the question is asking to roll an even number 2,4,6 and B, you have to multiply the probabilities of those happening.
Rolling an even number is 1/3 (2,4,6 out of 6), and rolling a B is 1/4(there is only one B out of A,B,C,D.)
If you multiply the two you get 1/12.
Hope that helps!