If p and q are prime numbers, how many divisors does the product p^6 * q^7 have?  Choose the most appropriate option:
A) 40 B) 56 C) 60 D) 62 E) 70

Rationale: "when a number n = a ^ x * b ^ y , where a and b are prime numbers , and x , y are positive integers , the number of divisors of n = ( x + 1 ) ( y + 1 ) therefore , the answer is b . 7 * 8 = 56"
Answer: B