问题详情

ThereasonsforthepopularityofTreasurybillsarethefollowingexceptthat______.
A．theyaretheonlymoneymarketinstrumentsaffordabletoindividualinvestors
B．theyarehighlyliquid
C．theyarerisk-free
D．theygivehigherreturnthanothermoneymarketinstruments

请帮忙给出正确答案和分析，谢谢！