Chemolithotrophs make use of

Options

A. organic compounds as a source of carbon
B. `CO_2` as a source of carbon
C. bacteriochlorophyll
D. bacterioviridin

Explanation

To answer the question "Chemolithotrophs make use of," we can follow these steps:

### Step-by-Step Solution:

1. **Define Chemolithotrophs**:
Chemolithotrophs are a type of bacteria that obtain energy by oxidizing inorganic substances. They are a part of the broader category of organisms that derive energy from chemical reactions involving inorganic compounds.

2. **Identify the Source of Carbon**:
Chemolithotrophs use carbon dioxide (CO2) as their primary source of carbon. This means they are autotrophic, as they can fix carbon from inorganic sources.

3. **Differentiate from Other Organisms**:
It is important to distinguish chemolithotrophs from chemoheterotrophs. Chemoheterotrophs obtain their carbon from organic compounds, while chemolithotrophs rely solely on inorganic carbon sources like carbon dioxide.

4. **Clarify Misconceptions**:
Some might confuse chemolithotrophs with other types of organisms that utilize organic compounds or specific pigments like bacterial chlorophyll. However, chemolithotrophs do not utilize these; they focus on inorganic molecules for energy and carbon.

5. **Summarize the Key Point**:
In summary, chemolithotrophs primarily make use of carbon dioxide as their source of carbon, which is an inorganic molecule.

### Final Answer:
Chemolithotrophs make use of carbon dioxide as a source of carbon.

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