First, B is not the answer, because if x = 0, the whole equation would've been 0.
A) -4/3 ; -1/2
Replace x and y with the 2 fractions, we have : 3/4 x (-4/3) + 1/2 = -1/2
-1 + 1/2 = -1/2 (true)
So, A is correct
But to make sure, we'll go over C and D also.
C) 4/3 ; 1/2
Replace x and y : 3/4 x 4/3 + 1/2 = 1/2
1 + 1/2 = 1/2 (not true)
So this is not the answer
D) 4 ; 3/2
Replace x and y : 3/4 x 4 + 1/2 = 3/2
3 + 1/2 = 3/2 (not true)
So, A is correct.