Two main components in Docker are:

The correct answer is: B. client, server.

A Docker client is a program that interacts with a Docker daemon. The client can be used to create, start, stop, and delete containers. The daemon is a program that runs on a host machine and manages the containers.

The master and slave components are not part of Docker. The master and slave components are part of a distributed computing system. In a distributed computing system, there are multiple computers that work together to solve a problem. The master computer is responsible for coordinating the work of the slave computers.

Here is a brief explanation of each option:

• Option A: master, slave. The master and slave components are not part of Docker. The master and slave components are part of a distributed computing system. In a distributed computing system, there are multiple computers that work together to solve a problem. The master computer is responsible for coordinating the work of the slave computers.
• Option B: client, server. The client and server components are part of Docker. The client is a program that interacts with a Docker daemon. The daemon is a program that runs on a host machine and manages the containers.
• Option C: client, master. The client and master components are not part of Docker. The client and master components are part of a distributed computing system. In a distributed computing system, there are multiple computers that work together to solve a problem. The master computer is responsible for coordinating the work of the slave computers.
• Option D: all of the above. This option is incorrect because it includes options that are not part of Docker.