Assertion : About the total number of species present on earth some extreme estimate range from 20 to 50 million.
Reason : We have no clear idea of how many species are yet to be discovered and described.
A. If both assertion and reason are true and the reason is the correct explanation of the assertion.
B. If both assertion and reason are true but reason is not the correct explanation of the assertion.
C. If assertion is true but reason is false.
D. If both assertion and reason are false.
