The correct answer is: C. both (a) and (b).
A computer is a physical system because it is made up of tangible components such as a motherboard, CPU, RAM, and hard drive. It is also a conceptual system because it is a tool that can be used to process information and solve problems.
Option A is incorrect because a computer is not just a physical system. It is also a conceptual system.
Option B is incorrect because a computer is not just a conceptual system. It is also a physical system.
Option D is incorrect because a computer is both a physical system and a conceptual system.
Option E is incorrect because the computer is a part of the firm’s physical system and conceptual system.