What is the product of all the prime factors of 15? Pick.
A) 12 B) 3 C) 4 D) 15 E) 20
factors : 3,5   3*5= 
<gadget id="calculator">3*5</gadget>
<output>15</output>
15   Answer : 15
<result>D</result>
What is the product of all the prime factors of 15?