Determine the correctness of otherwise of the following Assertion [A] and the Reason [R]. Assertion [A] : The crown of the outgoing larger diameter sewer is always matched with the crown of incoming smaller diameter sewer. Reason [R] : It eliminates backing up of sewage in the incoming smaller diameter sewer.

• Both [A] and [R] are true and [R] is the correct reason for [A]
• Both [A] and [R] are true and [R] is not the correct reason for [A]
• Both [A] and [R] are false
• [A] is true but [R] is false