If p and q are prime numbers, how many divisors does the product p^4 * q^9 have?	Select the correct option
A) 30
B) 35
C) 40
D) 50
E) 60

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 d . 5 * 10 = 50"
Answer: D