A. highly polluted
B. highly clean
C. highly productive
D. none of these
✅ The correct answer is option A.
The river which has high level of BOD is indicative of high pollution in the river as the dissolved oxygen available in the water is being used by the bacterias, and this result in less oxygen available to fish and other aquatic beings. Nitrates and phosphates contribute to high level of BOD.
The river which has high level of BOD is indicative of high pollution in the river as the dissolved oxygen available in the water is being used by the bacterias, and this result in less oxygen available to fish and other aquatic beings. Nitrates and phosphates contribute to high level of BOD.