Answer:
Option (B)
Explanation:
A river that is diverted to the irrigating farmland during a drought is an example of the human-caused disturbances to an ecosystem.
An ecosystem refers to a particular community within which the organisms exist and interact with each other. For example, fresh water ecosystem, desert ecosystem and forest ecosystem.
In the given situation, the river channel is disturbed by changing its flow direction. This is caused by the human activity, that changes the course of the river channel to the farmlands during a flood, so that the water can provide nutrient to the soil and prevent the soil from getting eroded.
Thus, by doing this, the river ecosystem gets affected, as a result of which the organisms existing in this ecosystem such as fishes are affected.
Hence, the correct answer is option (B).
