The net present value(NPV)method of investment project analysis assumes that the project's cash flows are reinvested at the( )计算投资项目分析的净现值（NPV）时，假定项目的现金流量在按以下哪项进行再投资( )。 A. Computed internal rate of return. 计算的内部回报率。 B. Risk-free interest rate. 无风险利率 C. Discount rate used in the NPV calculation. 净现值计算中使用的贴现率。 D. Firm's accounting rate of return. 公司的会计回报率。