$11.$ The different types of U$.$S$.$ government securities $($loan instruments$)$ are:a$.$ Treasury bills $($short$-$term securities$)$ b$.$ Treasury notes $($medium$-$term securities$)$c$.$ Treasury bonds $($long$-$term securities$)$d$.$ U$.$S$.$ savings bonds $($long$-$term, nonmarketable bonds$)$e$.$ All of the above