Firstly, how many units apart is -7 from -1 (the x-coordinates)? That would be 6 units away. Multiply 5/6 by 6:

Next, how many units apart is 2 from -4? That would be, again, 6 units. Multiply 5/6 by 6.

Now, since from -7 to -1 it's increasing, add 5 to -7:

-2 is the x-coordinate of M.
Next, since from 2 to -4 it's decreasing, subtract 5 from 2:

-3 is the y-coordinate of M.
Putting it together, M is at (-2,-3), or B.