First menstrual cycle starts at

Options

A. Parturition
B. Menopause
C. menarche
D. Implantation

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks when the first menstrual cycle occurs in females. This is a key aspect of female reproductive health.

2. **Analyzing the Options**: We have several options to consider:
- **Parturition**: This term refers to the act of giving birth. It is not related to the onset of menstruation.
- **Menopause**: This is the time in a woman's life when menstrual cycles cease, typically occurring in the 40s or 50s. This is also not related to the beginning of menstruation.
- **Menarche**: This term refers to the first occurrence of menstruation, which happens at puberty. This is a critical phase in a female's reproductive life.
- **Implantation**: This refers to the process during pregnancy when a fertilized egg attaches to the uterus. It does not relate to the menstrual cycle.

3. **Identifying the Correct Option**: Among the options, only "Menarche" directly refers to the first menstrual cycle. Therefore, it is the correct answer.

4. **Conclusion**: The first menstrual cycle starts at menarche, which typically occurs between the ages of 11 and 14, marking the onset of puberty in females.

### Final Answer:
The first menstrual cycle starts at **Menarche**.

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