Regarding complexity of digestive system in animals: 1. An incomplete digestive system has single opening to the outside of the body that serves as both mouth and anus. 2. A complete digestive system has two openings, mouth and anus.

Question

( a ) Both are incorrect
( b ) 1 is incorrect but 2 is correct
( c ) 1 is correct but 2 is incorrect
( d ) Both are correct