私募期货基金的有限合伙人只需投入很少比例的资金，但要参加基金的具体交易和日常管理活动。( )

The student was at________loss when________word came that he would be asked to come to

the office and explain his reason for being late for school. [ ]

A. a；the

B. /；/

C. the；the  

D. a；/