M = sqrt4 + cuberoot4 + fourroot4

sqrt4 = 2

cuberoot4 = at least 1

fourroot4 = at least 1

2+1+1 = 4 atleast

Therefore the answer is E, greater than 4.

Hope this helps.

Know these 2 values for gmat:

sqareroot of 2 ~= 1.4
squareroot of 3 ~= 1.7 (not for this problem)


sqrt of 4 is 2
fourth root of 4 can be expressed as 2 squared raised to 1/4 which is
2 raised to 1/2 by the exponent law (a ^ m) ^ n = a ^(mn)

4 raised to the power 1/4
= (2 ^ 2) ^ 1/4
= 2 ^ 1/2 = sqrt 2 = 1.4

So far we have 2+1.4 = 3.4

cuberoot of 4 must be within 1(cube is 1) and 2(cube is 8)

So greater than 4 is the answer.