[A]: Gibberellic acid when added to isolated aleurone layer, induces alfa-amylase activity. It acts at gene level.
[R]: GA may act at the gene level or just activates the inactive enzyme or interact to re- move enzyme inhibitor.

Options

A. (a) If both A and R are true and R is the correct explanation of A
B. (b) If both A and R are true but R is not the correct explanation of A
C. (c) If A is true and R is false
D. (d) If both A and R are false

Answer

### Step-by-Step Solution:

1. **Understanding Gibberellic Acid (GA)**:
- Gibberellic acid is a plant hormone known as a phytohormone. It plays a crucial role in various plant processes including seed germination, stem elongation, and breaking dormancy.

2. **Role of Aleurone Layer**:
- The aleurone layer is the outermost layer of the seed that contains stored proteins and enzymes. When seeds absorb water, the aleurone layer becomes active and begins to produce enzymes.

3. **Induction of Alpha-Amylase Activity**:
- When gibberellic acid is applied to the isolated aleurone layer, it induces the production of the enzyme alpha-amylase. This enzyme is essential for breaking down starches into sugars, which provide energy for the germinating seed.

4. **Mechanism of Action of GA**:
- Gibberellic acid acts at the gene level by promoting the transcription of genes responsible for synthesizing alpha-amylase. This means that GA can stimulate the expression of these genes, leading to increased enzyme production.
- Alternatively, GA may also activate pre-existing inactive enzymes or interact with inhibitors to remove them, allowing the enzyme to function.

5. **Conclusion**:
- Both the assertion (that GA induces alpha-amylase activity at the gene level) and the reason (that GA may act at the gene level, activate inactive enzymes, or remove enzyme inhibitors) are correct. The reason provides a valid explanation for the assertion.

### Final Answer:
Both assertion and reason are true, and the reason is the correct explanation of the assertion.