The north flowing rivers of Siberia are not of much use for navigation mainly because

A. They are too shallow in the dry season

B. The lower courses remain frozen for many months

C. They flow through uninhabited areas

D. They lack navigation facilities to ensure safety

Answer: Option B

Solution(By Examveda Team)

The north flowing rivers of Siberia are not of much use for navigation mainly because The lower courses remain frozen for many months.