Studying light effects on living organisms is

Options

A. Photoperiodism
B. Photomorphogenesis
C. Photobiology
D. Radiology.

Answer

To solve the question "Studying light effects on living organisms is," we need to analyze the options provided and determine which one correctly describes the study of light's effects on living organisms.

### Step-by-Step Solution:

1. **Understand the Options**:
- **Photoperiodism**: This refers to how plants respond to the length of light and dark periods in a day. It is specifically about the timing of biological events in relation to the light cycle.
- **Photomorphogenesis**: This is the process by which plants and some other organisms develop their form and structure in response to light. It focuses on growth and development influenced by light.
- **Photobiology**: This is the broader study of the effects of light on living organisms, encompassing various biological processes influenced by light.
- **Radiology**: This is a medical field that uses imaging techniques to diagnose and treat diseases. It is not related to the study of light effects on living organisms.

2. **Identify the Correct Definition**:
- Since the question asks specifically about the study of light effects on living organisms, we need to look for the term that encompasses all effects of light on biological systems.

3. **Choose the Best Option**:
- **Photobiology** is the most appropriate term as it covers the study of how light affects living organisms in various ways, including growth, behavior, and physiological processes.

4. **Conclusion**:
- The correct answer to the question is **Photobiology**.

### Final Answer:
The answer is **Photobiology**.