The question requires matching the rivers with their respective outflows.

Option 1:

A. Amu Darya - Outflow 1. Aral Sea

B. Dnieper - Outflow 3. Black Sea

C. Ural - Outflow 4. Caspian Sea

D. Yukon - Outflow 2. Bering Sea

Option 1 matches Amu Darya with the Aral Sea, Dnieper with the Black Sea, Ural with the Caspian Sea, and Yukon with the Bering Sea.

Therefore, the correct answer is Option 1: A-1, B-3, C-4, D-2.

Each river is matched with its respective outflow, and this answer follows the given codes.