Compared with the nervousness of driving in the rain or snow, it is ______ to sit in a train without any worry of bad weather.

A．more tired

B．less tiring

C．less tired

D．even more tiring

非政府投资项目，可由投资者自行确定基准收益率，确定基准收益率应以( )为基础。

A．投资风险和通货膨胀
B．资金成本和机会成本
C．投资风险和机会成本
D．资金成本和通货膨胀