ABA also acts as ................... hormones.

Explanation

**Step-by-Step Solution:**

1. **Identify ABA**: ABA stands for Abscisic Acid, which is a plant hormone.

2. **Determine the Function of ABA**: Abscisic Acid is primarily known for its role in plant responses to stress conditions.

3. **Define ABA's Role as a Hormone**: ABA acts as a stress hormone. It helps plants cope with adverse conditions such as drought.

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