Respuesta :

Answer:

  B.  4

Step-by-step explanation:

When you perform the multiplication, you get ...

  (x +c)(x +4) = x² + (c+4)x +4c = x² + 8x +4c

Then ...

  c + 4 = 8 . . . . coefficients of x must match

  c = 4 . . . . . matches choice B