Assertion : Proto-oncogenes are cellular genes required for normal growth.
Reason : Under normal conditions they could lead to the oncogenic transformation of the cell.

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 both assertion and reason are false.

Explanation

To solve the question, we need to analyze the Assertion and the Reason provided.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "Proto-oncogenes are cellular genes required for normal growth."
- This statement is true. Proto-oncogenes are indeed essential for normal cellular functions, including growth and division.

2. **Understanding the Reason**:
- The reason states that "Under normal conditions they could lead to the oncogenic transformation of the cell."
- This statement is false. Under normal conditions, proto-oncogenes do not cause oncogenic transformation. They only become oncogenes when they are mutated or expressed at high levels, often due to exposure to carcinogens.

3. **Evaluating the Relationship**:
- Since the assertion is true and the reason is false, the reason does not explain the assertion correctly.

4. **Selecting the Correct Option**:
- Based on the analysis:
- Assertion is true.
- Reason is false.
- Therefore, the correct answer is Option C.

### Final Answer:
**Option C: Assertion is true and Reason is false.**