Assertion. Now-a-days, the biodiversity is declining with an accelerated rate
reason. Exotic species are considered to be major cause of extinction of species

Options

A. If both are true with reason being correct explanation
B. both are true but reason is not correct explanation
C. assertion true but reason is wrong
D. both are wrong

Answer

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that biodiversity is declining at an accelerated rate nowadays. This is a true statement as numerous studies and reports indicate a significant loss of biodiversity due to various factors, primarily human activities.

2. **Understanding the Reason**:
- The reason provided is that exotic species are considered a major cause of extinction of species. While it is true that exotic species can contribute to the extinction of native species, they are not the sole or primary cause.

3. **Identifying the Current Extinction Episode**:
- We are currently experiencing the sixth mass extinction event, which is characterized by a much faster rate of species loss compared to previous extinction events. This current episode is largely driven by anthropogenic (human-induced) factors.

4. **The Role of Exotic Species**:
- Exotic species introduction can lead to competition with native species, predation, and disease transmission. However, it is just one of several factors contributing to biodiversity loss.

5. **The Evil Quartet**:
- The four major causes of extinction, known as the "Evil Quartet," include:
- Habitat loss and fragmentation (the primary cause)
- Overexploitation of species
- Alien species invasion (which includes exotic species)
- Co-extinction (where dependent species go extinct)

6. **Conclusion**:
- The assertion is true, but the reason is not entirely accurate. While exotic species contribute to extinction, they are not the major cause. Therefore, the correct answer is that the assertion is true, but the reason is false.

### Final Answer:
- The assertion is true, and the reason is false.