Answer:
for this case we have the following functions:
 f (x) = x + 8
 g (x) = -4x - 3
 Subtracting the functions we have:
 (f - g) (x) = f (x) - g (x)
 (f - g) (x) = (x + 8) - (-4x - 3)
 Rewriting:
 (f - g) (x) = x + 8 + 4x + 3
 (f - g) (x) = 5x + 11
 Answer:
 D. (f - g) (x) = 5x + 11