If {x} is the product of all even integers from 1 to x inclusive, what is the greatest prime factor of {14} + {12}?  Choose the correct choice from the following answers:
A) 23
B) 20
C) 15
D) 5
E) 2

Rationale: "soln : { 14 } + { 12 } = 14 * { 12 } + { 12 } = 15 * { 12 } answer : c"
Answer: C