The correct option is B All of the above
Impersonal pronouns are used when we want to refer to people in general, to things, unspecified objects or animals. 'It' is the most commonly used impersonal pronoun. There are several situations where we can use 'it'. Example: I am returning the dress because it isn't good. Here, the impersonal pronoun, 'it' is used to represent a noun, 'the dress' which is in neuter gender. 'One' is used to refer to a person in general or any unspecified object. Example: One can travel by bus to Bangalore. Here, we use 'One' to refer to any person who wants to travel to Bangalore. 'They' or 'You' are used similarly to address someone we may not know personally. Example: ‘They mostly speak Bengali in that part of the state’; ‘You won't find anything in this shop. (Maybe, to address myself or anyone in general). Hence, all these answers are correct as impersonal pronouns.