Avery is enrolling in a university next semester. There are 14 meeting times for physics classes and 18 meeting times for art history classes. 6 of the physics meeting times are in the evening and 4 of the meeting times for art history classes are in the evening. What is the probability that both of her classes meet in the evening?
A. 1/4
B. 3/16 C. 2/21 D. 1/24