Answer : 2. "Commercial grain farming"
Explanation :

Answer: B) Commercial grain farming Explanation: Monoculture is a typical characteristics of Commercial grain farming. Monoculture is the agricultural practice of producing or growing a single crop, plant, or livestock species, variety, or breed in a field or farming system at a time focussing commercial gains. Monoculture is widely used in both industrial farming and organic farming and has allowed increased efficiency in planting and harvest. Polyculture, where more than one crop is grown in the same space at the same time, is the alternative to monoculture.