The correct answer is c) G1.
During the G1 phase, also known as the first gap phase, the cell primarily grows in size, synthesizes mRNA and proteins necessary for DNA synthesis, and continues its normal metabolic activities. This phase is crucial for preparing the cell for the next stages of the cell cycle as it gathers the resources needed for DNA replication.
In contrast, during the S phase, DNA replication occurs, and during G2, the cell prepares for mitosis. Mitosis itself is the process of cell division, but G1 is vital for the cell’s growth and regular functions.