If the positive integer c has positive integer divisors a and b with c=a b, then a and b are said to be complementary divisors of c. Suppose that N is a positive integer that has one complementary pair of divisors that differ by 20 and another pair of complementary divisors that differ by 23 . What is the sum of the digits of N?
Answer Choices
A. 9
B. 13
C. 15
D. 17
E. 19