An area has reported higher instances of pollen allergy in humans. The area has good number of individuals of following plants or trees. Which one could be responsible for it?

Options

A. Carrot grass
B. Aloe vera
C. Fern
D. Rose bushes

Explanation

To determine which plant could be responsible for higher instances of pollen allergy in humans, we can analyze the options provided:

1. **Carrot Grass (Parthenium)**: This plant is known to produce a significant amount of pollen, which is a common allergen. It is notorious for causing allergic reactions, including respiratory issues such as asthma and bronchitis. Carrot grass is often found in areas with disturbed soil and is considered an invasive species in many regions.

2. **Aloe Vera**: While Aloe Vera has many medicinal properties, it is not known to produce allergenic pollen. It is primarily used for its gel and does not contribute significantly to pollen allergies.

3. **Fern**: Ferns reproduce via spores rather than pollen grains. Therefore, they are not a source of pollen allergies in humans.

4. **Rose Bushes**: While roses do produce pollen, they are not as commonly associated with severe allergic reactions compared to other plants. The pollen from roses is typically heavier and does not travel as far as that from plants like carrot grass.

Based on this analysis, the plant most likely responsible for the higher instances of pollen allergy in humans in the area is **Carrot Grass (Parthenium)**.

### Step-by-Step Solution:
1. **Identify the Problem**: The area has reported higher instances of pollen allergy in humans.
2. **Analyze the Options**: Look at the four plants provided: Carrot Grass, Aloe Vera, Fern, and Rose Bushes.
3. **Evaluate Each Plant**:
- **Carrot Grass**: Known for causing allergies due to its pollen.
- **Aloe Vera**: Not associated with pollen allergies.
- **Fern**: Does not produce pollen.
- **Rose Bushes**: Less commonly associated with severe allergies.
4. **Conclude**: The most likely cause of pollen allergy in this area is Carrot Grass (Parthenium).