What function does the CALL instruction perform?

The CALL instruction is fundamental in programming and computer operations. Its primary function is to facilitate the process of calling a subroutine or a separate block of code that performs a specific task. When a program reaches a CALL instruction, it temporarily suspends its current execution and jumps to the designated subroutine. This allows for code reusability and better organization within programs, as the same subroutine can be called from multiple places in the program without needing to replicate the code.

Once the subroutine is executed, control is returned back to the original program, allowing it to continue from the point where it left off. This mechanism is critical in structured programming, where complex tasks are often broken down into smaller, manageable functions or subroutines.

The other options do not accurately describe the function of the CALL instruction. For example, terminating a job execution, resetting systems, or executing jobs in parallel involves entirely different commands and functionalities that are not related to the direct action of calling a subroutine. Therefore, the role of the CALL instruction is specifically aligned with invoking subroutines to enhance program efficiency and clarity.