In human females, an event that reflects onset of reproductive phase is

Options

A. growth of body
B. changes in hair pattern
C. change in voice
D. menstruation

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for an event that signifies the beginning of the reproductive phase in human females.

2. **Analyzing the Options**:
- **Option A: Growth of the body** - This is a general change that occurs during puberty in both males and females.
- **Option B: Change in hair pattern** - This change also occurs in both genders during puberty.
- **Option C: Change in voice** - Similar to the previous options, this change is observed in both boys and girls during puberty.
- **Option D: Menstruation** - This is a specific event that occurs only in females and indicates the onset of the reproductive phase.

3. **Identifying the Unique Event**: Among the options, menstruation is unique to females and marks the beginning of their reproductive capability. It involves the shedding of the uterine lining and is a clear indicator of the reproductive phase.

4. **Conclusion**: The correct answer is **D: Menstruation**, as it is the event that specifically reflects the onset of the reproductive phase in human females.

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