Concept:Land for farming can be made more available by converting unusable or dry areas into productive agricultural land.
Explanation:The supply of land for agriculture is not completely fixed. It can be increased through land reclamation and irrigation.
Reclamation means creating new farmland from water bodies like seas, riverbeds, or swamps by draining and filling them.
Irrigation means supplying water to dry land so it becomes suitable for growing crops.
These methods bring more land into agricultural use.
Mechanised farming only improves how existing land is cultivated, not the total supply of land.
Converting building sites to farmlands may not be practical, and higher land prices only affect cost, not the physical supply.
Therefore, the best way to increase the supply of agricultural land is through reclamation and irrigation.
Answer:A. reclamation and irrigation