Step 1: The P5:
The UN Security Council has five permanent members, fixed since the UN's founding in 1945: the USA, Russia (successor to the USSR), the United Kingdom, France, and China.
Step 2: Checking the options:
China is the only country among the four listed that belongs to this group. North Korea, Japan, and India are all UN member states but none holds permanent Security Council membership.
Step 3: Note on India:
India has long sought permanent membership (referenced later in this same paper's Q27) but does not currently hold it — a common point of confusion, which is exactly why it is offered as a distractor here.
Step 4: Final Answer:
China.