Assertion `:` `1,3-` Butadiene is the monomer for natural rubber.
Reason `:` Natural rubber is formed though anionic addition polymerization.

Options

A. if both Assertion and Reason are true and reason is the correct explanation of the assertion.
B. if both assertion and reason are true but reason is not the correct expalanation of the assertion
C. if assertion is true, reason is false
D. both assertion and reason are false statements.

Explanation

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

### Step-by-Step Solution:

1. **Understanding the Assertion:**
- The assertion states that "1,3-Butadiene is the monomer for natural rubber."
- However, the actual monomer for natural rubber is **isoprene**, which is **2-methyl-1,3-butadiene**. Therefore, the assertion is **incorrect**.

2. **Understanding the Reason:**
- The reason states that "Natural rubber is formed through anionic addition polymerization."
- In reality, natural rubber is formed through **cationic addition polymerization**, not anionic. Therefore, the reason is also **incorrect**.

3. **Conclusion:**
- Since both the assertion and the reason are incorrect, we can conclude that the correct answer to the question is that **both assertion and reason are false statements**.

### Final Answer:
Both assertion and reason are false statements.