A block of mass 2 kg is free to move along the x–axis. It is at rest and from t =
0 onwards it is subjected to a time–dependent force F(t) in the x direction. The
force F(t) varies with t as shown in the figure. The kinetic energy of the block
after 4.5 seconds is
(A) 4.50 J (B) 7.50 J
(C) 5.06 J (D) 14.06 J.