单选题 Since you are in the preliminary stages of your project, you estimate that your project will most probably last 1 year-however, optimistic scenario is that it will get over within 6 months and pessimistic scenario is 18 months. This kind of estimate is also called ______ .

A、 definitive
B、 capital cost
C、 order of magnitude
D、 feasibility

【正确答案】 C

【答案解析】
[解析] 在项目筹备阶段, 你估算这个项目很可能在1年完成, 然而乐观估计这个项目会在6个月完成, 悲观估计这个项目历时大概为18个月。这种估算被称为 ______ 。
A) 确定的 B) 资本成本 C) 量级估算 D) 可行性
估算有不同的精确程度，量级估算准确度在-50%到+100%之间。