During drought, plants develop hormone

Options

A. Indole acetic acid
B. Naphthalene acetic acid
C. Indolebutyric acid
D. Abscisic acid.

Answer

**Step-by-Step Solution:**

1. **Understanding the Context**: During drought conditions, plants face water stress. They need to adapt to conserve water and survive.

2. **Identifying Plant Hormones**: There are several plant hormones, but we need to identify which one is specifically produced during drought conditions. The options given are:
- Indole acetic acid
- Naphthalene acetic acid
- Indole butyric acid
- Abscisic acid

3. **Recognizing the Role of Abscisic Acid**: Abscisic acid (ABA) is known to play a crucial role in plant responses to stress, particularly drought. It helps in closing the stomata, which are small openings on the leaves that allow for gas exchange.

4. **Mechanism of Action**: When ABA is produced, it signals the stomata to close. This closure reduces water loss through transpiration, which is essential for the plant's survival during periods of low water availability.

5. **Additional Functions of Abscisic Acid**: Besides closing stomata, ABA also has other functions:
- It delays food ripening.
- It inhibits cell division.
- It can affect the synthesis of other hormones, such as kinetin.

6. **Conclusion**: Given the role of abscisic acid in response to drought conditions, we can conclude that during drought, plants primarily develop the hormone abscisic acid.

**Final Answer**: During drought, plants develop the hormone **abscisic acid**.

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