The technique of communication by signs made with the fingers is called

Answer: Option C

Explanation:

The study of human races is called Ethnology.

The study of animal behaviour is called Ethology.

The study of origin and history of words is called Etymology.

Answer: Option C

Explanation:

The supposed communication of thoughts or ideas by means other than the known senses is called Telepathy.

The study of caves is called Spelelogy.

The branch of science concerned with earthquakes and related phenomena is called Seismology.

Answer: Option D

Explanation:

The study of bacteria is called Bacteriology.

The study of the movements and relative positions of celestial bodies interpreted as having an influence on human affairs is called Astrology.

Cultivation of trees and vegetables is called Arboriculture.

Answer: Option A

Explanation:

The study of sound is called Acoustics.
The science or art of flight is called Aeronautics.
The philosophy of fine arts Aesthetics.
The science of soil management is called Agronomy.

Answer: Option B

Explanation:

he collection and study of postage stamps is called Philately.

The branch of knowledge that deals with the structure, historical development, and relationships of a language or languages is called Philology.

The study and classification of speech sounds is called Phonetics.