One Word Substitution

Option (2) is correct.

Option (4) is correct.

Animals and plants that live in water are called aquatic animals.

Index is a detailed alphabetical listing of names, places, and topics along with the numbers of the pages on which they are mentioned or discussed.

A point where earth and sky seem to meet is called horizon.

Sleep loss is known as insomnia.

Cacophony refers to a harsh, discordant mixture of sounds. Discord is the closest synonym among the choices.

A cartographer is a person who draws or produces maps. The term is derived from the roots 'carta' (map) and 'graph' (to write/draw).

Choreography is the sequence of steps and movements in dance or figure skating. It is the art of designing these movements.

A collier is a coal miner or a ship used for carrying coal. The term is specific to the coal industry.

A vendor is a person or company offering something for sale, which is synonymous with a peddler or a seller.

A vampire is a mythological or folkloric being that subsists by feeding on the vital essence, generally in the form of blood, of the living.

Anthropology is the scientific study of humans, human behavior, and societies in the past and present.

A tachograph is a device fitted to a vehicle that automatically records its speed and the distance traveled, along with the driver's activity.

Taciturn describes a person who is reserved or uncommunicative in speech; saying little.