Assertion: Long bones are composed of cancellous bone.
Reason: Cancellous bone is denser and stronger than compact bone.
Both the assertion and reason are true, and the reason is the correct explanation of the assertion.
Both the assertion and reason are true, but the reason is not the correct explanation of the assertion.
The assertion is true, but the reason is false.
The assertion is false, but the reason is true.
The assertion in this question is that long bones are composed of cancellous bones. This assertion is false because long bones are actually composed of compact bone on the outer surface and cancellous bone on the inside. The cancellous bone, also known as trabecular bone or spongy bone, is less dense than compact bone and is found in the ends of long bones and the middle of other bones.
The reason given is that cancellous bone is denser and stronger than compact bone. This reason is false because the compact bone is actually denser and stronger than cancellous bone due to its tightly packed structure. Compact bone is found on the outer surface of bones and provides protection and support.
Hence, option 3 is the correct answer.