The linear function is expressed by the formula y = -3x + 1.5. Find the value of y for x = -1.5, 2.5, 4.
a) -7.5, 6, 10.5
b) 4.5, -8.5, -11.5
c) 6, 10.5, 15
d) -1.5, 4.5, 7.5