For DS problems, we shouls always get the relationships of the variables in the equation in order to know what conditions are needed to be able to answer the question
A=profits first year
B=profits second year
C=profits third year
1ºequation: B=(1+x)A
2ºequation: C=(1-y)B
Question to answer C>A? in other words (1-y)(1+x)A>A. Crossing off A in both sides of the equation: (1-y)(1+x)>1
Therefore we need to know if (1-y)*(1+x)>1,
but what is the relationship between x and y in this equation? It does not seem we know the relationship very well to be able to answer. Let's multiply the brackets (1-y)*(1+x)=1-y+x-x*y
Ok, so now we know that we need to know both the x+(-)y reationship and the x*y one
Option (1): 1-x<1 -y, which is -x<-y, which is x>y. This option tells me the x+(-)y relationship, but what about the multiplication? NOT SUFFICIENT
Option (2): xy/100<x-y. We inmediately see we have the x+(-)y reationship and the x*y one. No need to calculate. If we know the relationship between both, we can already conclude if C>A or not. Therefore: SUFFICIENT
Option B