Which of the following expressions accurately defines a set of all integers x such that x - y is divisible by x for any integer y?

a) x ∈ ℤ, where x - y is divisible by x
b) x ∈ ℤ, where y - x is divisible by x
c) x ∈ ℤ, where x + y is divisible by x
d) ( x ∈ ℤ, where y + x is divisible by x