Select the correct even from below that is most likely to occur during the three subphases of the interphase of the mitotic cell cycle .

Options

A. During `G_1` phase , the cell is metabolically active and replicates its DNA .
B. During S phase duplication of centrioles takes place.
C. The number of chromosomes becomes double in the synthesis phase .
D. Replication of DNA starts during the `G_2` phase and proteins are synthesized in order to prepare the cell for mitosis.

Answer

To solve the question regarding the events that occur during the three subphases of interphase in the mitotic cell cycle, we will analyze each of the provided statements one by one.

### Step-by-Step Solution:

1. **Understanding Interphase**:
- Interphase is the phase of the cell cycle where the cell prepares for division. It consists of three subphases: G1 (Gap 1), S (Synthesis), and G2 (Gap 2).

2. **Analyzing Each Statement**:
- **Statement A**: "During G1 phase the cell is metabolically active and replicates its DNA."
- **Analysis**: This statement is incorrect. While the cell is indeed metabolically active during the G1 phase, DNA replication does not occur until the S phase.

- **Statement B**: "During S phase duplication of centrioles takes place."
- **Analysis**: This statement is correct. In the S phase, DNA is replicated, and centrioles are also duplicated in preparation for cell division.

- **Statement C**: "The number of chromosomes becomes double in synthesis phase."
- **Analysis**: This statement is incorrect. Although the amount of DNA doubles during the S phase, the number of chromosomes remains the same until mitosis occurs.

- **Statement D**: "Replication of DNA starts during the G2 phase and proteins are synthesized in order to prepare the cell for mitosis."
- **Analysis**: This statement is incorrect. DNA replication occurs during the S phase, not the G2 phase. The G2 phase is primarily focused on protein synthesis and preparing the cell for mitosis.

3. **Conclusion**:
- The only correct statement among the options provided is **Statement B**: "During S phase duplication of centrioles takes place."

### Final Answer:
- The correct event that is most likely to occur during the three subphases of interphase of the mitotic cell cycle is **B. During S phase duplication of centrioles takes place.**