Kinetic energy of any object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity.The kinetic energy of any moving object depends upon its mass and speed.
Hence, option A is correct.
A.neither is completely right. Shawn is partly correct since kinetic energy depends on mass , but Greg is also partly right since it also depends on speed.