Select the correct option of haploid cells from the following groups :

Options

A. Primary oocyte, Secondary oocyte, Spermatid
B. Secondary spermatocyte, First polar body, Ovum
C. Spermatogonia, Primary spermatocyte, Spermatid
D. Primary spermatocyte, Secondary spermatocyte, Second polar body

Answer

To determine the correct option of haploid cells from the given groups, we need to analyze each option based on the ploidy level of the cells involved.

### Step-by-Step Solution:

1. **Understanding Ploidy Levels**:
- **Diploid (2N)**: Cells that have two sets of chromosomes (one from each parent).
- **Haploid (N)**: Cells that have one set of chromosomes, typically seen in gametes (sperm and egg).

2. **Analyzing Each Option**:
- **Option 1**: Primary oocyte, secondary oocyte, spermatid
- Primary oocyte: Diploid (2N)
- Secondary oocyte: Haploid (N)
- Spermatid: Haploid (N)
- **Conclusion**: This option contains both diploid and haploid cells.

- **Option 2**: Secondary spermatocyte, 1st polar body, ovum
- Secondary spermatocyte: Haploid (N)
- 1st polar body: Haploid (N)
- Ovum: Haploid (N)
- **Conclusion**: All cells in this option are haploid.

- **Option 3**: Spermatogonia, primary spermatocyte, spermatid
- Spermatogonia: Diploid (2N)
- Primary spermatocyte: Diploid (2N)
- Spermatid: Haploid (N)
- **Conclusion**: This option contains both diploid and haploid cells.

- **Option 4**: Primary spermatocyte, secondary spermatocyte, second polar body
- Primary spermatocyte: Diploid (2N)
- Secondary spermatocyte: Haploid (N)
- Second polar body: Haploid (N)
- **Conclusion**: This option contains both diploid and haploid cells.

3. **Final Conclusion**:
- The only option that contains exclusively haploid cells is **Option 2**: Secondary spermatocyte, 1st polar body, ovum.

### Answer:
**Option 2** is the correct answer as it contains only haploid cells.