Common nouns name general things, whereas proper nouns name
specific individuals or things. For example, 'man' is a common noun whereas Thomas
is a proper noun, a specific name for a particular man. Proper nouns always begin with a capital letter.
Option
A: 'Elephant', 'animal' and 'land' are all common nouns since they name general
things.
An elephant is a type of animal and an 'animal' is a living being. 'Land' names a part of the earth's surface.
Hence this option is the right
one.
Option B: 'Elephant' is a common noun and not a proper noun. It names a type of animal, but does not name a particular elephant.
Option C: 'Animal' and 'land' are not proper nouns. Proper nouns name a specific individual or a place. A proper noun like 'Tommy' names a pet dog (an animal) and a name like 'India' names a particular country (a part of land).
Option D: Proper nouns begin with capital letters 'E', 'A', and 'L' whereas these nouns begin with small letters 'e', 'a' and 'l'. (In any sentence or a phrase in a new line, the first letter of the first word is a capital.)
Hence options B, C and D are incorrect.