Assertion : Cretaceous period is called age of dinosaurs .
Reason : Fishes originated in Devonian period.

Options

A. A.If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion, then mark (1)
B. B.If both Assertion and Reason are true ,but the Reason is not the correct explanation of the Assertion, then mark (2).
C. C.If Assertion is true, but Reason is false , then mark (3)
D. D.If both Assertion and Reason are false. , then mark (4)

Answer

To solve the assertion and reason question, we will analyze both the assertion and the reason step by step.

### Step 1: Analyze the Assertion
- **Assertion**: "Cretaceous period is called the age of dinosaurs."
- The Cretaceous period is indeed known as the "Age of Dinosaurs" because it is the time when dinosaurs were the dominant terrestrial vertebrates. This period lasted from approximately 145 million years ago to 66 million years ago and is part of the Mesozoic Era, which is characterized by the presence of dinosaurs.

### Step 2: Analyze the Reason
- **Reason**: "Fishes originated in the Devonian period."
- The Devonian period, which lasted from about 419 to 359 million years ago, is known as the "Age of Fishes." During this time, a wide variety of fish evolved, and it is considered a significant period for the development of early fish species. However, it is important to note that while fishes did originate and diversify during this period, this fact does not directly explain why the Cretaceous period is referred to as the age of dinosaurs.

### Step 3: Conclusion
- Both the assertion and the reason are true statements:
- The assertion is true because the Cretaceous period is indeed called the age of dinosaurs.
- The reason is also true because fishes did originate in the Devonian period.
- However, the reason does not provide a correct explanation for the assertion. The origin of fishes in the Devonian does not relate to why the Cretaceous is known as the age of dinosaurs.

### Final Answer
- The correct conclusion is that the assertion is true, the reason is true, but the reason is not the correct explanation for the assertion.