If the rocket sled shown in the figure below starts with only one rocket burning, what is the magnitude of its acceleration? Assume that the mass of the system is 2.15103kg, the thrust F = 2.25104N, and the force of friction opposing the motion is known to be f = 605N. What is the magnitude of its acceleration? How would the acceleration change if all four of the rockets were burning?

a. The acceleration would be four times greater because the thrust is four times greater.

b. The acceleration would be four times greater because the net force is four times greater.

c. The acceleration would be less than four times as great because the frictional force does not change.

d. The acceleration would be more than four times as great because the frictional force does not change.