Which among the following is not the function of testes at puberty?
(i) Formation of germ cells
(ii) Secretion of testosterone
(iii) Development of placenta
(iv) Secretion of estrogen

Options

A. (i) and (ii)
B. (ii) and (iii)
C. (iii) and (iv)
D. (i) and (iv)

Explanation

To solve the question, we need to identify which of the options listed is not a function of the testes at puberty. Let's analyze each option step by step:

1. **Formation of germ cells (i)**:
- The testes are responsible for producing male gametes, which are sperm cells. This process is known as spermatogenesis and is a primary function of the testes during puberty.
- **Hint**: Think about what gametes are and where they are produced in males.

2. **Secretion of testosterone (ii)**:
- The testes secrete testosterone, which is the primary male sex hormone. This hormone is crucial for the development of secondary sexual characteristics during puberty, such as increased muscle mass and deeper voice.
- **Hint**: Consider the role of testosterone in male puberty and its effects on the body.

3. **Development of placenta (iii)**:
- The development of the placenta occurs in females during pregnancy. The testes do not have any role in this process, as they are male reproductive organs.
- **Hint**: Recall the functions of the placenta and which gender is involved in its development.

4. **Secretion of estrogen (iv)**:
- Estrogen is primarily a female hormone, produced mainly in the ovaries. While males do have some estrogen, it is not a primary function of the testes to secrete it, especially during puberty.
- **Hint**: Think about the primary hormones produced by male and female reproductive systems.

Now, summarizing the analysis:
- The functions of the testes at puberty include the formation of germ cells and the secretion of testosterone.
- The development of the placenta is not a function of the testes, as it is specific to females.
- The secretion of estrogen is not a primary function of the testes either.

Thus, the correct answer to the question "Which among the following is not the function of testes at puberty?" is:
- **(iii) Development of placenta**.

**Final Answer**: (iii) Development of placenta.