Since James gave Malcolm a head start of 20 feet, Malcolm's line should start at 20 feet. So that rules out A. They were obviously going further so they went more feet, So C is ruled out because it shows them not moving, plus James didn't get a 15 foot head start which is what the C graph shows. Finally it's not B because if you look at the key at the bottom of every graph, it says that Malcolm is the dotted line, and B shows James getting a 20 foot head start, not Malcolm.
