Assertion (A): A cross between a red flower bearing plant and a white flower-bearing plant of Antirrhinum is a case of incomplete dominance.
Reason ( R): This type of cross produces all plants having pink flowers.

Options

A. Both assertion (A) and reason ( R) are true and reason ( R) is the correct explanation of assertion (A).
B. Both assertion (A) and reason ( R) are true but reason ( R) is not the correct explanation of assertion (A).
C. Assertion (A) is true but reason ( R) is false.
D. Assertion (A) is false but reason ( R) is true.

Explanation

To solve the question, we need to analyze both the assertion and the reason provided regarding the inheritance pattern in Antirrhinum (snapdragon) flowers.

### Step-by-Step Solution:

1. **Understanding the Assertion (A)**:
- The assertion states that a cross between a red flower-bearing plant and a white flower-bearing plant of Antirrhinum is a case of incomplete dominance.
- Incomplete dominance occurs when the phenotype of the heterozygote (the offspring resulting from the cross) is intermediate between the phenotypes of the two homozygotes.

2. **Understanding the Reason (R)**:
- The reason states that this type of cross produces all plants having pink flowers.
- In the case of Antirrhinum, when a red flower (RR) is crossed with a white flower (rr), the resulting offspring (F1 generation) are heterozygous (Rr) and exhibit an intermediate phenotype, which is pink.

3. **Analyzing the Genetics**:
- The red flower genotype can be represented as RR (homozygous dominant).
- The white flower genotype can be represented as rr (homozygous recessive).
- When these two plants are crossed, the offspring will have the genotype Rr, which results in the pink flower phenotype due to incomplete dominance.

4. **Conclusion**:
- Both the assertion and the reason are correct. The assertion correctly identifies the type of inheritance (incomplete dominance), and the reason accurately describes the outcome of the cross (pink flowers).

5. **Final Answer**:
- Therefore, the correct option is that both assertion and reason are true, and the reason explains the assertion correctly.