Ripening of fruit is controlled by :

Options

A. Ethylene
B. Gibberellin
C. Auxin
D. Cytokinin

Answer

### Step-by-Step Solution:

1. **Identify the Question**: The question asks which substance controls the ripening of fruit.

2. **Understand the Options**: The options provided are:
- Option 1: Ethylene
- Option 2: Gibberellin
- Option 3: Auxin
- Option 4: Cytokinin

3. **Evaluate Each Option**:
- **Option 1: Ethylene**: Ethylene is a known phytohormone that plays a crucial role in the ripening of fruits. It promotes the ripening process by triggering various biochemical changes in the fruit.
- **Option 2: Gibberellin**: Gibberellin is primarily involved in seed germination and stem elongation. It does not play a direct role in fruit ripening.
- **Option 3: Auxin**: Auxin is a plant hormone that promotes stem elongation and inhibits lateral bud growth. It is not directly involved in the ripening of fruits.
- **Option 4: Cytokinin**: Cytokinin promotes cell division and growth of lateral buds, but it does not control fruit ripening.

4. **Conclusion**: Based on the evaluation, the correct answer is **Option 1: Ethylene**, as it is the hormone responsible for the ripening of fruits.

### Final Answer:
Ripening of fruit is controlled by **Ethylene**.