A train consists of 48 boxcars pulled by 2 engines. The boxcars are 15 meters long and the two engines are each 20 meters long. It crosses over a highway 24 meters wide at a speed of 14 m/s. How long does it take for the entire train to cross?  Select the correct option:
A) 56 sec
B) 63 sec
C) 72 sec
D) 81 sec
E) 88 sec

Rationale: a 56 sec d = 48 * 15 m + 2 * 20 m + 24 m = 784 m t = 784 m / 14 m / s = 56 s
Answer: A