Answer:
I'll assume m2 is m^2
m = ±4
Explanation:
1. m = ±4 m^2 = 16 YES. Both -4 and 4, when squared, are equal to 16
2. m = 4 This also works, but it doiesn't allow for the possibility that m is a -4
3. m = ±8 8^2 = 64 and (-8)^2 = 64 Don't work.
4. m = 8 8^2 = 64 Doesn't work.