Help with this proofs mcq (1 Viewer)

[sneak11]

For this question, the answer thats been given is D
What I’m confused about is can’t the answer be A or D - obviously C and B are wrong but what‘s stopping A from being a valid answer?

 

[carrotsss]

Consider x=0

 

[SadCeliac]

A is saying that for all x there exists a real y such that xy is 10
therefore y exists such that 10/x is real
but if x is 0 then y is not real

that's what i think the reason is