The subject pronouns can be divided into two general categories – Personal and impersonal pronouns. A personal pronoun is a pronoun that is associated with a particular person, like ‘he’, ‘she’ and ‘they’. While an impersonal pronoun is commonly used to speak about inanimate objects/things. ‘It’ is an impersonal pronoun that is used for this purpose. On the other hand ‘what’, ‘who’ and ‘which’ are interrogative pronouns that are used for asking questions. They are not impersonal pronouns. Thus the given statement is false.