Study of light absorption by chlorophyll is

Options

A. Absorption spectroscopy
B. Infra-red spectroscopy
C. Nuclear magnetic resonance spectroscopy
D. Emission spectroscopy.

Answer

To solve the question "Study of light absorption by chlorophyll is", we need to analyze the options provided and understand the context of each one.

### Step-by-Step Solution:

1. **Identify the Question**: The question asks about the study of light absorption specifically by chlorophyll. This indicates that we are looking for a technique that measures how chlorophyll absorbs light.

2. **Review the Options**:
- **Absorption Spectroscopy**: This technique measures the absorption of light (radiation) by a substance as a function of wavelength or frequency. It is directly related to how chlorophyll absorbs light.
- **Infrared Spectroscopy**: This technique is primarily used for analyzing gases and does not focus on light absorption in the visible spectrum, which is relevant for chlorophyll.
- **Nuclear Magnetic Resonance Spectroscopy (NMR)**: This technique is used to study the magnetic properties of atomic nuclei and is not related to light absorption.
- **Emission Spectroscopy**: This technique studies the light emitted by substances when they are excited and does not pertain to absorption.

3. **Determine the Correct Answer**: Since absorption spectroscopy is the technique that directly measures how chlorophyll absorbs light, it is the correct answer.

4. **Conclusion**: The study of light absorption by chlorophyll is best described by absorption spectroscopy.

### Final Answer:
The correct option is **absorption spectroscopy**.