Correct answer: A. Diversifying rural economy and market production
Explanation: The direct answer is A, diversifying the rural economy and market production. Agricultural expansion is not only an increase in cultivated land; it also includes growing different crops and producing for different needs. New crops gave cultivators more choices, could improve food variety, and could meet the demand of towns and markets. This made rural production more diverse and connected farming with trade. Option A is correct because it states this economic effect. Option B, ending the Sultanate, is wrong because introducing or spreading crops did not by itself end a political dynasty. Option C, demolishing forts, is unrelated to farming and military buildings. Option D, stopping painting, concerns art and has no logical connection with agricultural production. The reasoning chain is: new crops enter cultivation, farmers diversify what they grow, market demand encourages saleable crops, and rural-market activity expands. Exam cue: in history, agricultural change is often linked with food variety, commercial production and markets.