Which of the following statements is correct ?

Options

A. Animals can sow mitotic divisions in both haploid and diploid cells.
B. After S phase the number of chromosomes becomes double i.e., 2n to 4n.
C. During the `G_(2)` phase, proteins are synthesised in preparation for mitosis while cell growth continues.
D. S or synthesis phase marks the period during which RNA synthesis takes place.

Explanation

To determine which of the given statements is correct, we need to analyze each statement regarding cell division, particularly focusing on mitosis and the cell cycle phases.

### Step-by-Step Solution:

1. **Analyze the First Statement:**
- The statement claims that animals can show mitotic division in both haploid and diploid cells.
- **Evaluation:** This statement is incorrect. Animals primarily undergo mitotic division in diploid cells. Haploid cells in animals do not typically undergo mitosis.

2. **Analyze the Second Statement:**
- The statement suggests that after the S phase (synthesis phase), the number of chromosomes becomes double, changing from 2N to 4N.
- **Evaluation:** This statement is also incorrect. After the S phase, the amount of DNA doubles, but the chromosome number remains the same in terms of ploidy; it remains as 2N. Each chromosome is replicated, resulting in sister chromatids, but the count of distinct chromosomes does not change.

3. **Analyze the Third Statement:**
- The statement indicates that during the G2 phase, proteins are synthesized in preparation for mitosis while cell growth continues.
- **Evaluation:** This statement is correct. The G2 phase is indeed characterized by the synthesis of proteins necessary for mitosis, and cell growth continues during this phase.

4. **Analyze the Fourth Statement:**
- The statement claims that the S phase marks the period during which RNA synthesis takes place.
- **Evaluation:** This statement is incorrect. RNA synthesis primarily occurs during the G1 and G2 phases, not during the S phase. The S phase is focused on DNA replication.

### Conclusion:
After evaluating all the statements, the correct statement is the third one: "During the G2 phase, proteins are synthesized in preparation for mitosis while cell growth continues."