Here P(x,y) means that x is the divisor of y where x and y are the integers from the universe of discourse..
to make it simple let us say y=5 which is divisible by only 1 ,5.
y=15 divisible by 1,3,5,15
we can say that
every value of y will be divisible by some values of x..
or some x is only the divisor of all y.
now converting it to two place predicate...
∃x ∀y P(x,y) means some x is divisor of all y.
or
∀y∃xP(x,y) means all y is dividend of some x.
which means option B is the correct option (S2 and S3 is correct)