A toy train engine rests motionless on a track. One student begins pushing the engine to the right with a force of 2 newtons. At the same time, another student begins pushing the engine to the left with a force of 5 newtons. Which of the following best describes the resulting motion of the engine?
A It travels left at a constant speed.
B It travels left at an increasing speed.
C It travels right at a constant speed.
D It travels right at an increasing speed