Assertion $A$: Pollen grains are found in the form of fossils.
Reason $R$: Sporopollenin is seen in its outer layer.

• A
  Assertion $A$ and Reason $R$ both are correct,Reason $R$ is the correct explanation for Assertion $A$.
• B
  Assertion $A$ and Reason $R$ both are correct,Reason $R$ is not the correct explanation for Assertion $A$.
• C
  Assertion $A$ is correct and Reason $R$ is false.
• D
  Assertion $A$ is false and Reason $R$ is correct.