During adolescence, several changes occur in the human body. Mark one change associated with sexual maturation in boys.

Options

A. Loss of milk teeth
B. Increase in height
C. Cracking of voice
D. Weight gain

Explanation

**Step-by-Step Text Solution:**

1. **Understanding Adolescence**: During adolescence, boys undergo several physical changes as they transition into adulthood. This period is marked by sexual maturation, which involves various physiological developments.

2. **Identifying Changes**: Some of the key changes that occur in boys during this time include:
- Development of pubic hair
- Cracking of voice
- Increase in muscle mass
- Growth of hair in armpits and on the face
- Appearance of acne
- Loss of milk teeth

3. **Focusing on Sexual Maturation**: Among these changes, we need to identify one that is specifically associated with sexual maturation.

4. **Analyzing the Options**:
- **Development of pubic hair**: This is indeed a sign of sexual maturation.
- **Cracking of voice**: This change signifies the deepening of the voice, which is also a result of hormonal changes during sexual maturation.
- **Increase in muscle mass**: While this occurs during adolescence, it is not solely linked to sexual maturation.
- **Facial hair growth**: This is another sign of sexual maturation, but it typically occurs later.
- **Acne**: This is a common occurrence during adolescence but is not a direct indicator of sexual maturation.
- **Loss of milk teeth**: This is a normal developmental process and not specifically related to sexual maturation.
- **Weight gain**: This is a general change and not directly associated with sexual maturation.

5. **Conclusion**: The most appropriate change associated with sexual maturation in boys during adolescence is **cracking of voice**. This change indicates the development of secondary sexual characteristics.

**Final Answer**: Cracking of voice.

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