The correct answer is B: cold weather and icy rivers stopped Hudson from finding the Northwest Passage.
Henry Hudson faced significant environmental challenges during his voyages, particularly in the colder climates, which hampered his search for a passage through North America to Asia. His explorations were marked by difficult conditions that included ice and harsh weather, particularly when navigating rivers and passages in the northern regions. Although he did interact with Native Americans and learn from them, the primary obstacles he encountered were not related to hot weather or tropical diseases.