sud be A.
the question basically asks
is GM/GW < GM/GW * SM/SW?

I says: SW/SM < GM/GW * SM/SW
so clearly, SM/SW > GM/GW * SM/SW
This means, SM/SW > GM/GW

So obviously, GM/GW >GM/GW * SM/SW.
And a definite answer to the question is NO.

I think the question asks: compare GM/GW to (GM + SW)/ (GW + SM)
In order to compare a/b to c/d, we can indirectly compare a*d and b*c (a,b,c,d must be positive). For example
if ad>bc then a/b>c/d. Then I'll try to compare GM * (GW+ SM) to GW * (GM +SW).
GM * (GW+ SM) = GM*GW + GM*SM
GW * (GM +SW) = GW*GM + GW*SW
both have GM*GW, so eliminate it. I'll compare only GM*SM to GW*SW

1. SW/SM < (GM+SW)/(GW+SM) or
SW*(GW+SM) < (GM+SW)*SM or SW*GW + SW*SM < GM*SM + SW*SM, eliminate the bold item in both sides :
SW*GW < GM*SM, hey look, this is what we need to know to solve the above-mention ratio. => Suff

2. SW/SM > W/M or SW/SM > (SW+GW)/(SM+GM), then using the same method:
SW*(SM+GM) > (SW+GW)*SM or SW*SM + SW*GM> SW*SM + GW*SM, eliminate SW*SM in both sides :
SW*GM>SM*GW, this is not the relationship we're looking for. We need SW to be with GW and SM to be with GM.
Hence Insuff.

IMO: A, only I suff.

OA is A