AMC 10A 2012 Problem 6

The product of two positive numbers is 9 . The reciprocal of one of these numbers is 4 times the reciprocal of the other number. What is the sum of the two numbers?

Answer Choices
A. \dfrac{10}{3}
B. \dfrac{20}{3}
C. 7
D. \dfrac{15}{2}
E. 8