Photolithotrophs (photoautotrophs) obtain energy from

Options

A. Radiations and carbon from inorganic compounds
B. Radiations and carbon from organic compounds
C. Organic compounds
D. Inorganic compounds.

Answer

### Step-by-Step Solution:

1. **Understanding the Terms**:
- Photolithotrophs, also known as photoautotrophs, are organisms that can produce their own food using light energy. The prefix "photo" indicates the use of light (or radiation), and "lithotroph" refers to organisms that use inorganic substances as electron donors.

2. **Identifying the Energy Source**:
- Photolithotrophs obtain energy primarily from light (radiation). This energy is used in the process of photosynthesis to convert inorganic substances into organic compounds.

3. **Understanding Carbon Source**:
- In addition to light, photolithotrophs utilize carbon from inorganic compounds, specifically carbon dioxide (CO2), to synthesize organic molecules like carbohydrates.

4. **Evaluating the Options**:
- The options provided are:
- A) Radiation and carbon from inorganic compounds
- B) Radiation and carbon from organic compounds
- C) Organic compounds
- D) Inorganic compounds
- Analyzing these options:
- Option A is correct because photolithotrophs use light (radiation) and carbon from inorganic sources (like CO2).
- Option B is incorrect as photolithotrophs do not obtain carbon from organic compounds.
- Option C is incorrect because it does not mention the energy source (light).
- Option D is incomplete as it does not specify the energy source.

5. **Conclusion**:
- The correct answer is **A) Radiation and carbon from inorganic compounds**.