The three cells found in a pollen grain when it is shed at 3-celled stage are

Explanation

To answer the question about the three cells found in a pollen grain when it is shed at the three-celled stage, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Pollen Grain Structure**:
- A pollen grain is initially formed in the anther of a flower and consists of cells that will eventually participate in fertilization.

2. **Pollen Grain at the Three-Celled Stage**:
...