Statement 1:if x/y<0 that means that either x is negative or y is negative that is why the resultant ans is -ve so it also implies that xy is not greater than 0.
Statement 2: if x+y<0 it may have many cases possible like for eg :
Case 1:x=-5 and y=-5 so x+y<0 and xy>0
Case2:x=-10 and y=5 so x+y<0 but xy is not greater than 0.
So nothing can be inferred from statement 2 but statement 1 alone is sufficient.
Ans is c