A. They will remain arrested in G0. Wrong

B. They will cross the R point and will arrest in G1/S transition point. Wrong

C. They will be committed to enter and complete another round of cell cycle
if not disturbed. Right but you won't be able to see the completion of the cell cycle, if you harvest the cells at t=16 (during S phase).

D. They will complete several rounds of cell cycle until contact inhibition will cause cell cycle arrest in G0. Wrong since the maximal exposure to CS is 16 hrs (mid S phase). Once the cells are reexposed to the starvation medium, the levels of cyclin D will decline, and the cells will be arrested in G0 again, provided they are not harvested before this stage.