Which of the following sentences contains a relative pronoun?

• The sentence containing a relative pronoun is "She bought the dress that was on sale."

Relative pronouns introduce relative clauses and relate them to the noun or pronoun that they modify. In this sentence, "that" is a relative pronoun that introduces the relative clause "that was on sale," which provides additional information about the noun "dress."

Pronoun ৯ প্রকার। যথা :
1.Personal pronoun : I, He, They
2.Demonstrative pronoun : This, Those
3.Relative pronoun : Which, Where, that.
4.Reciprocal pronoun : Each other, One another
5.Interrogative pronoun : Who, Whom
6.Indefinite pronoun: None, Several
7.Distributive pronoun : Each, Either
8.Possessive pronoun: Theirs, Ours
9.Reflexive pronoun : Myself, Ourselves

Source: Cambridge dictionary