項(xiàng)目經(jīng)理剛接手一個項(xiàng)目,但是總經(jīng)理下周就要和客戶開會討論,希望項(xiàng)目經(jīng)理能盡快做出一個關(guān)于項(xiàng)目的成本估算,那么項(xiàng)目經(jīng)理應(yīng)該采用哪種方法?A.類比估算B.參數(shù)估算C.自下而上估算D.三點(diǎn)估算