Step 1: Recall definitions.
- Router: A network device that forwards data packets between networks → (II).
- Ethernet Card: Also known as NIC (Network Interface Card) → (IV).
- Ring: A type of network topology → (I).
- PAN (Personal Area Network): A type of network (like LAN, MAN, WAN) → (III).
Step 2: Matching.
So: (A) - (II), (B) - (IV), (C) - (I), (D) - (III).
Final Answer:
\[
\boxed{(A)-(II), (B)-(IV), (C)-(I), (D)-(III)}
\]