John's favorite number is odd and has prime factors that do not repeat. Which of the following numbers is his favorite? Select the correct option
A) 27
B) 75
C) 121
D) 105
E) 147
Factor each option.   A 27 = 3*3*3   B 75 = 3*5*5   C 121 = 11*11   105 105 = 3*5*7   E 147 = 3*7*7   105 is the only choice with no repeating prime factors
<result>D</result>
John's favorite number is odd and has prime factors that do not repeat. Which of the following numbers is his favorite?