Answer:
The option (d) is correct
Step-by-step explanation:
Solution
System calls are made with a: Kernel thread created upon process start
A computer program request service from a kernel using System calls. It is a kernel thread which is created when a process starts. System calls allows services of the operating system to the user program between the Application programming interface (API).
A kernel thread: refers to processes and interfere or stops handlers; it is the entity managed by the system scheduler. A kernel thread moves inside an operation, but can be called by any other instructions (execution) in the system.