The subway was crowded with passengers going home from market, most of ________carrying heavy bags and baskets full of fruits and vegetables they had bought there.

A．whom

B．them

C．who

D．which

关于投标有效期，下列说法正确的是( )。

A．投标有效期从投标文件提交之日计算
B．拒绝延长投标有效期的投标人无权收回投标保证金
C．投标有效期从招标文件规定投标截止之日起计算
D．招标人不承担投标有效期延长对投标造成的相应损失