Clearly, D must be staged on Friday. A must be staged before E i.e., order AE must be followed. But E cannot be staged on last day. Also, B must be staged immediately after F i.e., order FB must be followed. But B cannot precede D. So, F and B can be staged on Monday and Tuesday and A and E on Wednesday and Thursday. C, which cannot be staged on Tuesday shall be staged on Saturday. Thus, the order followed will be :
Monday |
Tuesday |
Wednesday |
Thursday |
Friday |
Saturday |
F |
B |
A |
E |
D |
C |
Clearly, A immediately follows B.
So, the answer is (a).