Concept:Crop rotation is a cultural practice that disrupts the life cycle of insect-pests.
Explanation:Insect-pests of crops often depend on a specific host plant for food and reproduction.
When the same crop is grown continuously in a field, pest populations build up over time.
Crop rotation breaks this cycle by planting a different crop in the following season.
This removes the preferred host plant, causing pests to starve or move away.
It also interrupts the breeding and egg-laying stages of many insects.
Therefore, among the given choices, crop rotation is the most effective cultural method for controlling insect-pests.
Cover-cropping and mulching mainly protect soil, while organic manuring improves soil fertility; none directly target pest life cycles.
Answer:C. crop rotation