What is the equation of the tangent line to the curve y = 6x - x2 - 5 at the point (4,3)?

A. 2x + y = 11
B. x - y = 1
C. 2x -y = 5
D. x + y = 7

also please please please explain how you got your answer! I swear, I have never had problem with anything in my life as hard as I have with calculus