User level threads are threads that are visible to the programmer and are unknown to the kernel. The operating system kernel supports and manages kernel level threads. Three different models relate user and kernel level threads:
Statement (A): (i) The many-to-one model maps many user threads to one kernel thread. (ii) The one-to-one model maps one user thread to one kernel thread. (iii) The many-to-many model maps many user threads to a smaller or equal number of kernel threads.
Statement (B): (i) The many-to-one model maps many kernel threads to one user thread. (ii) The one-to-one model maps one kernel thread to one user thread. (iii) The many-to-many model maps many kernel threads to a smaller or equal number of user threads.
Which of the following is true?

1. A(A) (A) is true; (B) is false
2. B(B) (A) is false; (B) is true
3. C(C) Both (A) and (B) are true
4. D(D) Both (A) and (B) are false

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