Which one of the following pairs is not correctly matched ?

Options

A. Adenine derivative - kinetin
B. Carotenoid derivative - ABA
C. Terpenes - IAA
D. Indole compounds - IBA

Answer

To determine which pair is not correctly matched, we will analyze each of the given pairs step by step.

### Step 1: Analyze the first pair - Adenine derivative: Kinetin
- Kinetin is indeed a synthetic cytokinin and is derived from adenine.
- This pair is correctly matched.

**Hint:** Kinetin is a synthetic cytokinin derived from adenine.

### Step 2: Analyze the second pair - Carotenoid derivative: Abscisic Acid
- Abscisic acid (ABA) is known to be derived from carotenoids.
- This pair is also correctly matched.

**Hint:** Abscisic acid plays a role in fruit abscission and is derived from carotenoids.

### Step 3: Analyze the third pair - Terpenes: Indole-3-Acetic Acid (IAA)
- Indole-3-acetic acid (IAA) is an auxin and is derived from the indole group, not terpenes.
- This pair is incorrectly matched.

**Hint:** IAA is derived from indole, not terpenes.

### Step 4: Analyze the fourth pair - Indole compounds: Indole-3-Butyric Acid (IBA)
- Indole-3-butyric acid (IBA) is indeed a derivative of indole-3-acetic acid (IAA).
- This pair is correctly matched.

**Hint:** IBA is a derivative of IAA, which is an indole compound.

### Conclusion
The pair that is not correctly matched is the third one: Terpenes: Indole-3-Acetic Acid (IAA).

**Final Answer:** The incorrect pair is "Terpenes: Indole-3-Acetic Acid (IAA)".