FSH acts on the `ul((A))` cells and stimulates secretion of `ul((B))` which help in the process of `ul((C))`.

Answer

To solve the question, we need to identify the components labeled as (A), (B), and (C) based on the information provided about FSH (Follicle Stimulating Hormone) and its role in human reproduction.

### Step-by-Step Solution:

1. **Identify the Action of FSH**:
- FSH is known to act on specific cells in the male reproductive system. In this context, it stimulates certain cells in the testes.

**Hint**: Think about the types of cells in the testes that are influenced by hormones.

2. **Determine the Target Cells (A)**:
- FSH acts on the **Sertoli cells** in the testes. These cells are crucial for the nourishment and support of developing sperm cells.

**Hint**: Recall the function of Sertoli cells in the testes.

3. **Identify the Secretion (B)**:
- When FSH stimulates the Sertoli cells, they secrete various factors, including **inhibin** and **androgen-binding protein (ABP)**. These factors are essential for the development of sperm.

**Hint**: Consider what substances Sertoli cells produce that are important for sperm development.

4. **Determine the Process (C)**:
- The secretion from Sertoli cells aids in the process of **spermatogenesis**, which is the formation of sperm cells from spermatogonial stem cells.

**Hint**: Think about the overall process that leads to the production of mature sperm.

### Final Answer:
- (A) Sertoli cells
- (B) Inhibin / Androgen-binding protein (ABP)
- (C) Spermatogenesis

### Summary:
FSH acts on the **Sertoli cells** (A) and stimulates the secretion of **inhibin** or **androgen-binding protein (ABP)** (B), which help in the process of **spermatogenesis** (C).