Subject: mathqa
Question: in a class of 50 students , 20 play baseball , 15 play cricket and 11 play football . 7 play both baseball and cricket , 4 play cricket and football and 5 play baseball and football . if 18 students do not play any of these given sports , how many students play exactly two of these sports ?
Option: 
A: 10
B: 46
C: 67
D: 68
Answer: A