4. Let f(x)=-2x+7 and g(x)=-6x+3. Find f×g and state its domain
A. 12x^2-48x+21;all real numbers
B. -14x^2+36x-18;all real numbers except x=7
C. -14x^2+36x-18;all real numbers
D. 12x^2-48x+21;all real numbers except x=1