Assertion :- Companion cells are essential for functioning of sieve tubes.
Reason :- The companion cells help in maintaining the pressure gradient in sieve tubes.
A. If both Assertion & Reason are True & Reason is a correct explanation of the Assertion.
B. If both Assertion & Reason are True but the Reason is a correct explanation of the Assertion.
C. If Assertion is True but the Reason is False.
D. If both Assertion & Reason are false.
