“Cryptography” is the branch of science which deals with:

Explanation: Correct Answer: Cryptography is the practice and study of techniques for secure communication, especially using codes and ciphers to protect information from unauthorized access. Other Options: (A) Crimes and criminals - This is criminology. (C) Physical features of particular areas - This refers to topography. (D) Heat and effects of heat on the earth - This falls under thermodynamics or meteorology.