Step 1: Understanding the regions and their capitals.
Each region in Spain has its corresponding capital city:
- La Rioja → Logroño
- Asturias → Oviedo
- Aragón → Zaragoza
- Extremadura → Mérida
Step 2: Match them accordingly.
A-IV, B-I, C-II, D-III
Step 3: Verification.
All the cities correctly correspond to their respective autonomous communities.
Step 4: Conclusion.
The correct option is (4) A-IV, B-I, C-II, D-III.