Assertion : Multicellular organisms have higher survival value than the unicellular organisms.
Reason : Dead cells are replaced by new cells in multicellular organisms.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion.
B. If both assertion and reason are true but reason is not the correct explanation of assertion.
C. If assertion is true but reason is false.
D. If both assertion and reason are false.

Explanation

Multicellular organisms are made up of many cells whereas in unicellular organisms only one cell is present. Death of some cells or injury does not kill a multicellular organism as dead cells are replaced by new cells while in unicellular organisms, death of a cell leads to death of an organism. Because of increased efficiency, organisation, division of labour, proper internal environment and protection, multicellular organisms possess higher survival value than the unicellular organisms.