Assertion:The outermost covering of a dicotyledonous seed in the seed coat.
Reason:The seed coat has two layers-outer testa and inner helium.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion.
B. If both assertion and reason are true but reason is not the correct explanation of assertion.
C. If assertion is true but reason is false.
D. If assertion and reason are false.

Explanation

To solve the question, we need to analyze both the assertion and the reason provided.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "The outermost covering of a dicotyledonous seed is the seed coat."
- This is true. In dicotyledonous seeds, the seed coat is indeed the outermost layer that protects the seed.

2. **Understanding the Reason**:
- The reason states that "The seed coat has two layers - outer testa and inner hilum."
- This statement is partially incorrect. The seed coat does have two layers, but the inner layer is typically referred to as the "tegmen," while the "hilum" is actually the scar on the seed where it was attached to the ovary, not a layer of the seed coat.

3. **Conclusion**:
- Since the assertion is true and the reason is false, we conclude that the correct option is that the assertion is true but the reason is false.

### Final Answer:
- The correct option is: Assertion is true but the reason is false.