Answer
A.CD
Cause theCD is the mid point of triangle ADB which divides triangle in two half if you look carefully you can understand the diagram ☺️☺️
One then because we are adding
You already have all you need. Just put in it the slope-intercept form: y=mx+b where m is the slope and b is the y-intercept so
y=7x-4
Its B
the answer is above..................................ok