Assertion : The period for which pollen grains remain viable is highly variable.
Reason : Viability of pollen grain depends some extent on the prevailing temperature and humidity
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.