If k is a multiple of 3 and k=(m2)nk=(m2)n, where m and n are prime numbers, which of the following must be a multiple of 9?  Choose the correct option.
A) m^2  B) n^2  C) mn  D) mn^2  E) (mn)^2
must be a multiple of 9   m and n are prime...lets have 2 and 3   now either of then can be a 3...   a) m can be 2 and n = 3...out   b) n can be 2 and m = 3...out   c) m = 2 and n=3 ...out   d) n can be 2 and m = 3...out   e) m = 2/3 or n = 3/2 both satisfies .......must be a multiple of 9   ANSW(mn)^2R:(mn)^2
<result>E</result>
If k is a multiple of 3 and k=(m2)nk=(m2)n, where m and n are prime numbers, which of the following must be a multiple of 9?