Assertion: Animal cells in vitro divide till they fill the surface of the culture vessel and then stop growing. Reason: Animal cells can be grown up to only limited generations.
a) Both assertion and reason are true, and reason is the correct explanation of the assertion.
b) Both assertion and reason are true, but reason is not the correct explanation of the assertion.
c) Assertion is true, but reason is false.
d) Assertion is false, but reason is true.