PS question from GMAT PREP test

[Fab_Vr6]

If n and y are positive integers, and 450y= n^3, which of the following must be an integer?

I) y/(3x2^2 x5)

II)y/(3^2 x2x5)

III) y/(3x2x5^2)

A) none
B)I only
C)II only
D)III only
E) I II III

[Prasanna]

If n and y are positive integers, and 450y= n^3, which of the following must be an integer?

I) y/(3x2^2 x5)

II)y/(3^2 x2x5)

III) y/(3x2x5^2)

A) none
B)I only
C)II only
D)III only
E) I II III

Here 450n should be a cube of an integer. 450 can be factorized as 5*5*3*3*2. For 450y to be a cube y could be equal to 5*3*2*2. From this we know y/(3*2*2*5) will be an integer definitely. Hence option B.

Whats the OA?

[jayhawk2001]

Another vote for B.