Chlorophyll is light trapping pigment, which carries light reaction during photosynthesis. The light reaction occurs in the thylakoid which is a coin like structure stacked over each other to form grana of the chloroplast.
So, the correct answer is 'In the grana of chloroplasts'.

**Chlorophyll is present in the grana of chloroplasts.**

Chloroplasts are the organelles found in plant cells that are responsible for photosynthesis. Photosynthesis is the process by which plants convert sunlight into energy-rich molecules such as glucose. Chlorophyll is the pigment responsible for capturing sunlight and initiating the process of photosynthesis.

Here is a detailed explanation of why chlorophyll is present in the grana of chloroplasts:

**1. Chloroplast Structure:**
Chloroplasts have a complex structure that consists of various compartments. The two main compartments are the grana and the stroma. The grana are stacks of disc-shaped structures called thylakoids, whereas the stroma is the fluid-filled matrix surrounding the grana.

**2. Location of Chlorophyll:**
Chlorophyll molecules are embedded in the thylakoid membranes, which are part of the grana. These membranes contain specialized protein complexes called photosystems that facilitate the capture and conversion of light energy during photosynthesis.

**3. Light-Dependent Reactions:**
The grana are primarily involved in the light-dependent reactions of photosynthesis. During these reactions, chlorophyll molecules in the thylakoid membranes absorb light energy and use it to generate ATP (adenosine triphosphate) and NADPH (nicotinamide adenine dinucleotide phosphate), which are energy-rich molecules that drive the synthesis of glucose in the subsequent dark reactions.

**4. Chlorophyll Absorption Spectrum:**
Chlorophyll molecules are specifically designed to absorb certain wavelengths of light, primarily in the red and blue regions of the electromagnetic spectrum. This is why plants appear green to our eyes, as chlorophyll reflects green light while absorbing other wavelengths for photosynthesis. The chlorophyll molecules in the grana are arranged in a way that maximizes their exposure to sunlight, allowing for efficient light absorption.

**Conclusion:**
In summary, chlorophyll is present in the grana of chloroplasts because it is embedded in the thylakoid membranes. The grana are the sites where chlorophyll captures light energy during the light-dependent reactions of photosynthesis. This arrangement ensures efficient light absorption and enables plants to convert sunlight into chemical energy.