What is the greatest positive integer x such that 3^x is a factor of 9^5? Choose the most appropriate option:
A) 5 B) 9 C) 10 D) 20 E) 30
What is the greatest positive integer x such that 3^x is a factor of 9^5?   9^5 = (3^2)^5 = 3^10   C. 10
<result>C</result>
What is the greatest positive integer x such that 3^x is a factor of 9^5?