Fill in the blank with the most appropriate words.
That pen isn’t ________, ________ is a green one.
A) My / my
B) His / he
C) Mine / mine
D) I / me
E) Her / its

Hint: Pronoun takes the place of a noun or pronoun is a word that substitute for a noun or noun phrase. For example: I, me, he, she, herself, you, many, who, whose, somebody, everybody and etc.

Complete answer:
The meaning of the word unique is ‘special, individual, uncommon and unusual’. So, as per the question For answering this question students should be aware of the types of pronouns i.e. Personal, possessive, reflexive, reciprocal, relative, demonstrative, interrogative and indefinite pronouns. So, to fill the blank with the most appropriate type of pronoun.

Option A) My / my – is an incorrect answer because ‘my/ my’ is grammatically incorrect and makes the sentence illogical. Though my is a possessive pronoun but using ‘my’ in the blank does not give the sense in the sentence. Thus, this is an incorrect answer.

Option B) His / he – is an incorrect answer because ‘his’ is the possessive pronoun and ‘he’ is the personal pronoun. So, the use of ‘his/ he’ is inappropriate in the blank and thus, this is an incorrect answer.

Option C) Mine / mine – is the correct answer because the blank requires a possessive pronoun. Possessive pronouns define the possession of something and show the ownership of something. For example: my, our, mine, your, their and etc. So, the use of this option in the blank is the most appropriate answer: That pen isn’t mine, mine is a green one - telling that pen belongs to me, ownership of pen. Thus, this is the correct answer.

Option D) I / me – is an incorrect answer because the use of ‘I and me’ is incorrect and does not make sense in the sentence. Thus, this is an incorrect answer.
Option E) Her / its – is an incorrect answer because ‘her / its’ does not make sense in the blank and makes the sentence meaningless. Thus, this is an incorrect answer.

That pen isn’t mine, mine is a green one.

Hence, the correct answer is Option C.

Note: In the first blank and second blank, the pronoun "mine" will be used because 'mine' is a possessive pronoun that is used to relate a particular object, person or a group. In the given sentence, the speaker is relating a person to himself. And other options are incorrect because they are not possessive nouns. Possessive nouns include: His, mine, ours, theirs, her.