Which line has a slope of -5?

A negative slope makes a line go down to the right.
The line C goes up to the right, so that is not it.
slope = -5 = rise/run = -5/1
For every 5 the y-coordinate goes down, the x-coordinate goes 1 to the right.
Only line B goes down 5 and right 1, so the answer is line B.
Answer: Line B