Six cousins, A, B, C, D, E and F, are going on a bike trip to Laddakh. Each one is riding a different bike. E is riding slower than F. A is riding faster than C but slower than D. D is riding slower than B but faster than F. C is riding faster than F. Who, among these six, is riding the fastest?

(1) E is riding slower than F. → E < F
(2)A is riding faster than C but slower than D. → C < A < D
(3) D is riding slower than B but faster than F. → F < D < B
(4) C is riding faster than F. → F < C

Arrange the order from slowest to fastest:
From condition (1):
E < F
From condition (4):
E < F < C
From condition (2):
E < F < C < A < D
From condition (3):
E < F < C < A < D < B
Thus, B is the fastest.
Therefore, the correct option is  (d) B