What is the primary function of system software?

The primary function of system software is to provide the fundamental infrastructure that allows computer hardware and application software to communicate effectively. This class of software includes the operating system, which manages hardware resources, and utility programs that perform maintenance tasks. The operating system acts as an intermediary between users and the computer hardware, facilitating the operation of applications and ensuring that hardware components function together smoothly.

While running applications faster and serving as the main interface for users are important aspects provided by the system software, they are more specific functions rather than the overall purpose. The efficiency in calculations can also result from system software optimization, but again, it doesn't encompass the primary role of system software as a whole. Thus, option A accurately captures the essence of system software's primary function.