Eric plans to compete in a triathlon. He can average 2 miles per hour in the \dfrac{1}{4}-mile swim and 6 miles per hour in the 3 -mile run. His goal is to finish the triathlon in 2 hours. To accomplish his goal what must his average speed, in miles per hour, be for the 15 -mile bicycle ride?

**Answer Choices**

A. \dfrac{120}{11}

B. 11

C. \dfrac{56}{5}

D. \dfrac{45}{4}

E. 12