Microorganisms are decomposers as they break down complex organic substances into simple inorganic substances.

Reason (R): Mushrooms are decomposers that ensure bidirectional flow of nutrients.

A) Both assertion and reason are true, and the reason is the correct explanation of the assertion.
B) Both assertion and reason are true, but the reason is not the correct explanation of the assertion.
C) Assertion is true, but the reason is false.
D) Assertion is false, but the reason is true.