During embryonic development the heart beat begins at the end of

Options

A. `1^("st")` trimester
B. `2^("nd")` trimester
C. `1^("st")` month
D. `2^("nd")` month

Answer

**Step-by-Step Solution:**

1. **Understanding Embryonic Development**: Embryonic development refers to the early stages of development of an embryo, which occurs during the first trimester of pregnancy, typically the first three months.

2. **Identifying Key Organs**: Among the organs that develop during this time, the heart is one of the first to form. It is crucial for establishing the circulatory system in the developing embryo.

3. **Timing of Heartbeat Initiation**: The heartbeat begins shortly after the heart has formed. This typically occurs at the end of the first month of embryonic development.

4. **Confirming the Timeframe**: The first trimester lasts for three months (approximately 0 to 12 weeks). The heart starts to beat towards the end of the first month, which is around 4 weeks into the pregnancy.

5. **Conclusion**: Therefore, the correct answer to the question is that the heartbeat begins at the end of the first month of embryonic development.

**Final Answer**: The heartbeat begins at the end of the first month of embryonic development.

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