Ascaris completes its life cycle in

Options

A. Only in man
B. Man and sheep
C. Man and mosquito
D. Man and cow

Explanation

To determine where Ascaris completes its life cycle, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Ascaris**: Ascaris is a type of roundworm, specifically Ascaris lumbricoides, which is known to infect humans.

2. **Life Cycle Characteristics**: Ascaris has a monogenetic life cycle, meaning it completes its life cycle in a single host. This is an important characteristic to consider when analyzing the options provided.

3. **Evaluating the Options**:
- **Option A (Only in man)**: This suggests that Ascaris completes its life cycle solely in humans.
- **Option B (Man and sheep)**: This implies that Ascaris can complete its life cycle in both humans and sheep, which is incorrect.
- **Option C (Man and mosquito)**: This suggests that Ascaris can complete its life cycle in humans and mosquitoes, which is also incorrect.
- **Option D (Man and cow)**: This implies that Ascaris can complete its life cycle in both humans and cows, which is incorrect as well.

4. **Conclusion**: Since Ascaris completes its life cycle only in humans, the correct answer is **Option A (Only in man)**.

### Final Answer:
Ascaris completes its life cycle in **only in man**.

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