Arrange the following events in order of happening :- (A) Spermiation (B) Insemination
(C) Spermatogenesis (D) Ejaculation

Options

A. `A to D to C to B`
B. `C to A to D to B`
C. `A to C to D to B`
D. `C to A to B to D`

Answer

To arrange the events in order of happening, we need to understand each term related to human reproduction:

1. **Spermatogenesis (C)**: This is the process of forming sperm cells in the seminiferous tubules of the testes. It is the initial step in male gamete formation.

2. **Spermiation (A)**: After spermatogenesis, spermiation occurs, which is the release of mature sperm from the seminiferous tubules into the lumen of the tubules.

3. **Ejaculation (D)**: This is the process where sperm is expelled from the male reproductive system through the urethra during sexual intercourse.

4. **Insemination (B)**: This is the introduction of sperm (in the form of semen) into the female reproductive tract during copulation.

Now, arranging these events in the order they occur:

1. **Spermatogenesis (C)** - Formation of sperm.
2. **Spermiation (A)** - Release of sperm from the testes.
3. **Ejaculation (D)** - Expulsion of sperm from the male body.
4. **Insemination (B)** - Introduction of sperm into the female reproductive tract.

Thus, the correct order is: **C, A, D, B**.

### Final Order:
1. Spermatogenesis (C)
2. Spermiation (A)
3. Ejaculation (D)
4. Insemination (B)