The graph above is for the linear function y = mx + b. Which of the following could represent the graph of y = c • mx + b where c is a positive number less than 1?

Since c is a positive number, then the function will remain to keep a negative slope. Due to c is less than 1 the line will not become steeper, so a fraction y=1/3(-x) -3 for example. The closer one would be an option B (Check below)
1) Let's find the function (-3,0) and (0,-3)
So the slope:
So the function is y=-x-3
Since c is a positive number, then the function will remain to keep a negative one. Due to c is less than 1 the line will not become steeper, so something like y=1/3(-x) -3 for example. The closer one would be an option B