Which phytohormone is used to increase the size of the apple?

Explanation

**Step-by-Step Solution:**

1. **Understanding Phytohormones**: Begin by defining what phytohormones are. Phytohormones, or plant hormones, are naturally occurring small organic molecules that influence physiological changes in plants.

2. **Role of Phytohormones**: Recognize that these hormones act as chemical messengers in plants, coordinating various cellular activities and processes.

3. **Identifying the Relevant Phytohormone**: Among the various phytohormones, identify which one is specifically known for increasing fruit size.

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