A matrix is singular when the determinant is 0
so we need to check the matrix that has determinant 0
option A :
Determinant = (9*-2) - (8*-3) = -18 + 24 = 6
option B :
Determinant = (7*2) - (12*-8) = 14 + 96 = 110
option C :
Determinant = (-6*4) - (-7*8) = -24+56= 32
option D :
Determinant = (-12*3) - (-4*9) = -36 + 36 =0
Option D is a singular matrix
