Car X and Car Y are travelling in the same direction in two different lanes on a long straight highway. Car X is travelling at a constant speed of 90\:km/h and has a length of 5\:m. Car Y is travelling at a constant speed of 91\:km/h and has a length of 6\:m. Car Y starts behind Car X and eventually passes Car X. The length of time between the instant when the front of Car Y is lined up with the back of Car X and the instant when the back of Car Y is lined up with the front of Car X is t seconds. The value of t is
Answer Choices
A. 39.6
B. 18
C. 21.6
D. 46.8
E. 32.4