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

Answer: Option D

Explanation:

The study of ancient writing systems and the deciphering and dating of historical manuscripts is called Paleography.

A person's facial features or expression, esp. when regarded as indicative of character or ethnic origin is called Physiognomy.

The production of silk and the rearing of silkworms for this purpose is called Sericulture.

Answer: Option B

Explanation:

Exercises developing or displaying physical agility and coordination is called Gymnastics.

The science that deals with the earth's physical structure and substance, its history, and the processes that act on it is called Geology.

The study of the microscopic structure of tissues is called Histology.

Answer: Option A

Explanation:

The scientific study of birds is called Ornithology.

The correct or accepted pronunciation of words is called Orthoepy.

The method and practice of teaching, esp. as an academic subject or theoretical concept is called Pedagogy.

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 C

Explanation:

The use or study of images or symbols in visual arts is called Iconography.

Literature dealing with saints is called Hagiology.

The treatment of illness through the use of water, either internally or through external means such as steam baths is called Hydropathy.