The slope field for the differential equation dy/dx=(3y)/(xy+5x) will have vertical segments when

A) x=0, only

B) y=0, only

C) y=-5, only

D) y=5, only

E) x=0 or y=-5

Im not sure what this question is asking for, we have never used the term slope field in class. I do know that something with a vertical slope has a derivative of undefined though. Please help