$ Duck billed platypus is viviparous
! Duck is a type of platypus.

Options

A. If both As and R are correct and R is correct explanation of As
B. If both As and R are correct but R is not correct explanation of As
C. If As is correct, R is wrong
D. If both As and R are wrong.

Answer

To solve the question regarding the assertion and reason about the duck-billed platypus, we will analyze each statement step-by-step.

### Step 1: Analyze the Assertion
The assertion states: "Duck-billed platypus is viviparous."
- **Viviparous** refers to animals that give birth to live young rather than laying eggs.
- The duck-billed platypus is a unique mammal that actually lays eggs, which means it is **oviparous**.

**Conclusion**: The assertion is **incorrect**.

### Step 2: Analyze the Reason
The reason states: "Duck is a type of platypus."
- The duck is a bird and belongs to a different class of animals (Aves), while the platypus is a mammal (Mammalia).
- Therefore, the statement that "duck is a type of platypus" is also **incorrect**.

**Conclusion**: The reason is **incorrect**.

### Step 3: Determine the Relationship Between Assertion and Reason
Both the assertion and the reason have been found to be incorrect.

### Step 4: Evaluate the Options
Given the analysis:
- If both assertion and reason are correct: **No**
- If both assertion and reason are correct but reason is not the correct explanation of assertion: **No**
- If assertion is correct and reason is wrong: **No**
- If both assertion and reason are wrong: **Yes**

**Final Conclusion**: The correct answer is that both the assertion and reason are incorrect.