Which explains why few animal species live in a fast-flowing river?

Question 5 options:

Cold water lowers dissolved oxygen levels.

Currents prevent accumulation of most organic matter.

Few animals are adapted to withstand high-speed water.

Frothing water reflects sunlight away from autotrophs.

The correct option is B) Currents prevent accumulation of most organic matter.

Explanation:

In fast - flowing river, organic matter will not get accumulated. The organic matter will be in constant motion due to the currents. Hence, life would be very difficult in fast - flowing rivers. The organisms living in fast - flowing rivers will not receive enough food as there will be minimal organic matter. Also, due to the currents, the organisms will have difficulty maintaining themselves. Hence, very few species live in fast-flowing rivers.