2. Concepts and Definitions II: True or False? And Why? i) It is not necessary for an agency MBS to have credit enhancement i) In the calculation of modified duration there is no need for a prepayment model (or assumption) iii) If the funding gap of a defined benefit pension plan increases, the funding ratio will more likely decrease iv) There is no credit risk in an interest rate swap v) Immunized portfolio should not be rebalanced periodically