項(xiàng)目發(fā)起人要求項(xiàng)目經(jīng)理進(jìn)行項(xiàng)目預(yù)算評(píng)估,而進(jìn)行量級(jí)評(píng)估的所有要素并不具備,項(xiàng)目經(jīng)理應(yīng)該怎么辦? A、創(chuàng)建WBS B、收集需求 C、制定范圍說(shuō)明書 D、定義活動(dòng)