B Suppose you plan to build a house. Your first step will be to find a right piece of land. 从首段这两句可以得到答案
A 从后文描述It will show the number of rooms, their position and size, and other parts, which must be noticed, such as windows, doors, and electric outlets. 可得出结论
A The builder's estimate depends on the plan, but the final plan depends on the builder's estimate. final表示最终的关系