Head lice attain nutrition by nutrition.

Options

A. parasitic
B. carnivorous
C. saprophytic
D. insectivorous

Explanation

**Step-by-Step Solution:**

1. **Understanding Head Lice**: Head lice are small parasitic insects that live on the scalp and feed on human blood. They are commonly found in the hair of the head.

2. **Identifying the Type of Nutrition**: To determine how head lice obtain their nutrition, we need to understand the different types of nutritional strategies:
- **Parasitic**: Organisms that live on or in a host and derive nutrients at the host's expense.
- **Carnivorous**: Organisms that primarily eat other animals.
- **Saprophytic**: Organisms that feed on dead or decaying organic matter.
- **Insectivorous**: Plants that trap and digest insects for nutrients.

3. **Analyzing the Options**:
- **Parasitic**: This is applicable to head lice as they live on the human scalp and feed on blood.
- **Carnivorous**: Not applicable, as head lice do not eat other animals.
- **Saprophytic**: Not applicable, as head lice do not feed on dead matter.
- **Insectivorous**: Not applicable, as head lice are not plants and do not trap insects.

4. **Conclusion**: Since head lice feed on the blood of their human host, the correct answer is **parasitic**.

**Final Answer**: Head lice attain nutrition by **parasitic** means.

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