When examining cells in the laboratory, you notice that a particular cell has half as much DNA as the surrounding cells. This observation can be explained if this cell's cell cycle halted at checkpoint .

G1

Explanation:

The cell cycle is divided into 2 main phases namely:

While the m phase is the active division phase, the interphase is further divided into:

Hence, if a cell is noticed to have half as much DNA as the surrounding cells, it means that particular cell's cell cycle halted at G1. The cell has not been able to synthesize DNA unlike the surround cells.

your answer should be c) enjoy!