Assertion : Pili are tubular structures present in bacteria which help in conjugation. Reason : Formation of pili is controlled by F+ or fertility factor.

• A. If both assertion and reason are true and reason is the correct explanation of assertion.
• B. If both assertion and reason are true but reason is not the correct explanation of assertion.
• C. If assertion is true but reason is false.
• D. If both assertion and reason are false.