Determine the graph that has the following properties:
domain: (- infinity, 4) , [4, infinity)
range: [0, infinity)
axis of symmetry: x=4

We have that

domain: (- infinity, 4) , [4, infinity)
range: [0, infinity) 
axis of symmetry: x=4

1) the only two graphs with axis of symmetry x = 4 are graph B and graph D
2) graph B> the range is [0, infinity) 
3) graph D> the range is (-infinity, 0]
4) the domain graph B and graph D is the same

therefore

the answer is
the graph B

the formula of a slope:

we have the points (-2, 7) and (2, 3). substitute:

answer: the slope is equal -1.