Consider a mortgage-backed security (MBS) with a waterfall payment structure and three tranches. From which of the following tranches should the investor purchase a bond to minimize exposure to default risk but not exposure to prepayment risk? Multiple Choice The senior tranche The mezzanine tranche The junior tranche Consider a mortgage-backed security (MBS) with a waterfall payment structure and three tranches. From which of the following tranches should the investor purchase a bond to minimize exposure to default risk but not exposure to prepayment risk? Multiple Choice The senior tranche The mezzanine tranche The junior tranche