What is the quotient (4-x)/(x^2+5x-6) ÷ (x^2-11x+28)/(x^2+7x+6) in simplified form? State the restrictions on the variable.
A. (-(x+1))/((x-1)(x-7)), x≠1,x≠7
B. (-1)/((x-7)), x≠7
C. (-1)/((x-7)), x≠1,x≠-6,x≠4
D. (-(x+1))/((x-1)(x-7)), x≠1,x≠-6,x≠4,x≠7