Just take an example and try to solve it by using options:
suppose, x=10 and y=5
begin
q := 0 // q = 0
r := x // r = x i.e. r = 5 as value of taken as 10
while r ≥ y do // 10 ≥ 5 ; TRUE (first iteration)
begin
r := r - y // r = 10 - 5 = 5
q := q + 1 // q= 0 + 1 = 1
end
while r ≥ y do // 5 ≥ 5 ; TRUE (second iteration)
begin
r := r - y // r = 5 - 5 = 0
q := q + 1 // q= 1 + 1 = 2
end
while r ≥ y do // 0 ≥ 5 ; FALSE (third iteration)
end
at the end of while loop
we get value of r = 0 and q = 2
x= 10 and y = 5
Now one by one put these values in given option
and thus, option B satisfied i.e.
{x=qy+r∧r<y} // x = 2*5 + 0 = 10 and 0 < 5