Answer:
Option B, The population of paddlefish will decrease, while the population of zooplankton will increase.
Step-by-step explanation:
Since, it is given that humans living around the river started hunting the paddlefish thus their population will definitely decrease. As the number of paddlefish decreases the extent to which they feed on zooplanktons will also decrease. Thus, the population of zooplanktons will increase with no or limited disturbance.
Population of lamprey which feed on paddlefish will start decreasing as their food i.e paddlefish has started declining.
Thus, option B is the correct answer.