The type of pronoun is called an "indefinite pronoun."
Naturally, they are used when the noun (person, place or thing) is unspecified.
SOME examples are ... all, any, everything, everyone, none, nobody, some, someone, etc....
Travelogue is a literary genre that tells about travel experiences of the autor. In this case, options B, D and E describe the literary elements present in a travelogue.