Passengers _____ fasten their seat belts immediately after taking their seats. The belts should remain buckled during the flight whether or not the “fasten seat belt” light is on.

A．shall

B．might

C．need

D．would

根据现行会计制度规定，对于销货业务，销货单位即使在向客户提供现金折扣的情况下，也应按总价法确认应收账款的入账价值。 ( )