To solve this question, the user needs to know the different types of testing techniques used in cybersecurity. The user must identify the type of testing in which activities are performed to find active machines, open ports, available services, identifying the OS, and mapping the network.

Now, let's go through each option and explain why it is right or wrong:

A. Passive Scanning: This option is incorrect because passive scanning is a type of testing in which the tester monitors network traffic and collects data without actively engaging with the network.

B. Social Engineering: This option is incorrect because social engineering is a type of attack that exploits human behavior to gain access to systems or information.

C. Scanning: This option is correct. Scanning is a type of testing that involves actively probing a network to identify active machines, open ports, available services, identifying the OS, and mapping the network.

D. Fuzzing: This option is incorrect because fuzzing is a type of testing that involves sending random or invalid data to a system to identify vulnerabilities.

The Answer is: C