Assertion: Fossils provide evidence that evolution of life forms has taken place on earth.
Reason: Fossils are remains of hard parts of life-forms found in rocks, and studying them in different sedimentary layers helps determine the geological period in which they existed.

Both Assertion (A) and reason (R) are correct and R is the correct explanation of A.

The correct answer is Option (1) –Both Assertion (A) and reason (R) are correct and R is the correct explanation of A.

Assertion: Fossils provide evidence that evolution of life forms has taken place on earth.

• True: Fossils are crucial in studying the history of life on Earth. They offer direct evidence of past organisms and their changes over time, which supports the theory of evolution.

Reason: Fossils are remains of hard parts of life-forms found in rocks, and studying them in different sedimentary layers helps determine the geological period in which they existed.

• True: Fossils are typically found in sedimentary rocks. These rocks form in layers over millions of years, and each layer can contain fossils from different periods. By studying the sequence of these layers and the fossils within them, scientists can infer the age of the fossils and the time periods during which the organisms lived.

Connection between Assertion and Reason:

• The reason provides the basis for why fossils are evidence for evolution. The study of fossils in different sedimentary layers shows that life forms have varied over time and that new life forms have appeared at different points in Earth's history. This variation and the emergence of new forms over time are key aspects of the theory of evolution.

Therefore, the correct answer is: Both assertion and reason are true, and reason is the correct explanation of assertion.