Final answer:
Early European settlements were primarily located near natural water sources, which were crucial for agriculture, sustenance, trade, and transportation.
Step-by-step explanation:
The location of early European settlements best reflects their proximity to natural water sources. Historical evidence suggests that access to fresh water was a critical factor in the development of early cities and civilizations.
These settlements relied on water for agriculture, which supported larger populations and led to the development of cities. Waterways were also essential for trade and transportation, vital to the economic growth of these early settlements. Therefore, the answer to the question is A. Their proximity to natural water sources.