Heart is absent in

Options

A. Nereis and Amphioxus
B. Pheretima
C. Nereis
D. Amphioxus

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks which organisms do not possess a heart. We need to analyze the provided options to determine which of them lack a heart.

2. **Analyzing the Options**:
- **Option A: Nereus and Amphioxus**:
- Nereus, a type of polychaete worm, has a primitive circulatory system but does not have a true heart.
- Amphioxus, a cephalochordate, also lacks a heart and instead has vascular spaces and contractile vessels.
- **Option B: Ferritima**: This is an earthworm, which is known to have structures often referred to as "false hearts" (lateral hearts) that help in circulation.
- **Option C: Nereus**: As mentioned earlier, Nereus does not have a true heart.
- **Option D: Amphioxus**: Similar to Nereus, Amphioxus does not have a heart.

3. **Conclusion**: Both Nereus and Amphioxus do not possess a true heart. Therefore, the correct answer is **Option A: Nereus and Amphioxus**.

### Final Answer:
The heart is absent in **Nereus and Amphioxus**.

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