Q. Two persons X and Y have been asked to show that a certain problem p is NP-complete. X shows a polynomial time reduction from the 3-SAT problem to p and Y shows a polynomial time reduction from p to 3-SAT. From these reduction it can be inferred that

• (A) P is NP-complete
• (B) P is NP-hard but not NP-complete
• (C) P is in NP but not NP-complete
• (D) P is neither NP-hard nor in NP