Class – Mammalia : 1. The skin of mammals is unique in possessing hair. 2. External ears or pinnae are absent in most species. 3. Different types of teeth are present in the jaw. Regarding 1,2 and 3:

Question

( a ) 1 is correct but 2 and 3 are incorrect
( b ) 1 is incorrect but 2 and 3 are correct
( c ) 2 is incorrect but 1 and 3 are correct
( d ) 3 is incorrect; 1 and 2 are correct