Preening is a behavior commonly observed in birds and other animals. It refers to the act of grooming oneself to maintain clean, healthy feathers or fur. In this context, the concept of preening is being applied metaphorically to the cultivation of a specific crop.

Option 1: Coffee. Preening is not associated with the cultivation of coffee. Coffee cultivation involves planting, growing, and harvesting coffee beans.

Option 2: Cashew. Preening is not associated with the cultivation of cashew. Cashew cultivation involves growing cashew trees and harvesting cashew nuts.

Option 3: Rubber. Preening is not associated with the cultivation of rubber. Rubber cultivation involves growing rubber trees and extracting latex from them.

Option 4: Tea. Preening is associated with the cultivation of tea. Tea plants, specifically Camellia sinensis, are cultivated and pruned to encourage healthy growth and production of tea leaves.

In conclusion, option 4 (tea) is the correct answer as preening, similar to the grooming behavior in animals, is associated with the cultivation of tea plants to maintain their health and productivity.