Class – Mammalia : 1. Sexes are separate 2. Fertilisation is internal. 3. They are always viviparous 4. Development is direct. Regarding 1,2,3 and 4:

Question

( a ) 3 is incorrect; 1,2 and 4 are correct
( b ) 1 and 2 are correct but 3 and 4 are incorrect
( c ) 4 is incorrect but 1, 2 and 3 are correct
( d ) 2 is incorrect; 1,3 and 4 are correct