Study the following:
A. Testosterone influences the male secondary sexual characters
B. Gestation period in rabbit is approximately 276 days
C. Bulbo-uretheral glands secrete a vaginal lubricant
D. Placenta secretes estrogen
The correct answer is:

Options

A. C and D
B. A and B
C. A and D
D. B, C and D

Explanation

To solve the question, we need to analyze each statement provided and determine which ones are correct.

### Step-by-Step Solution:

1. **Statement A: Testosterone influences the male secondary sexual characters.**
- This statement is **correct**. Testosterone is a hormone produced by Leydig cells in the testes and is responsible for the development of male secondary sexual characteristics such as deepening of voice, increased muscle mass, and hair growth.

2. **Statement B: Gestation period in rabbit is approximately 276 days.**
- This statement is **incorrect**. The gestation period for rabbits is approximately 30 to 32 days, not 276 days.

3. **Statement C: Bulbo-urethral glands secrete a vaginal lubricant.**
- This statement is **incorrect**. The bulbo-urethral glands (also known as Cowper's glands) are present in males and secrete a pre-ejaculatory fluid that helps lubricate the urethra, but they do not secrete vaginal lubricant as they are absent in females.

4. **Statement D: Placenta secretes estrogen.**
- This statement is **correct**. The placenta acts as an endocrine organ during pregnancy and secretes hormones including estrogen and progesterone, which are crucial for maintaining pregnancy.

### Conclusion:
From the analysis, the correct statements are A and D. Therefore, the correct answer is option **3: A and D**.

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