According to the given equation, James' rate is 15 feet per second.
Now, let's find Steven's rate

Let's replace the points (2,42) and (4,84), where


As you can observe, Steve runs faster his rate is 21 feet per second.
A is the answer.
Now, we have to use the point-slope formula to find Steven's equation

The image below shows the graph of both lines.
As you can observe in the graph, James will catch him up at (10,210).