题目解析:
A选项用price of rice定位到:the average price per kilogram doubled,dboubled对应A选项的increase。
B选项用amount of rice对应该段第4句话:
The average annual volume of rice exported from Siam grew from under 60 million kilograms per year in the late 1850s to more than 660 million kilograms per year at the turn of the century. grew对应B选项的increase。
C选项用nutritional quality定位,原文中没有提及。
D选项用amount of land定位到该段的最后一句:This growth was achieve as the result of the collective decisions of thousands of peasants families to expand the amount of land they cultivated, clear and plant new land, or adopt more intensive methods of agriculture. expand对应D选项的increase。