Given below are two statements:
Assertion A: A process involves a library function to create a thread.
Reason R: The threads make system calls to convey their resource and I/O requirements to the Kernel.

Explanation

Assertion A is true: user-level threads are typically created, scheduled and managed by a user-space threading library (e.g. pthread_create) without the kernel being aware of individual threads at all. Reason R is also true in general — running threads do issue system calls to request resources and perform I/O. But R does not explain A: a library routine can create a thread entirely in user space regardless of whether, or how, that thread later makes system calls, so the two facts are unrelated causally. Hence both statements are true but R is not the correct explanation of A, option (ii).