11. The duration of a callable bond is the duration of an otherwise equal non- callable bond because a. Equal to; they have the same cash flows, same tenor, and same yield. b. Greater than; if the bond is called it increases the tenor of the bond which mechanically increases its duration. c. Greater than; callable bonds have higher cash flows making their durations longer. d. Less than; callable bonds are often not called which makes their durations less than that of comparable non-callable bonds. e. Less than; the duration of a callable bond can only be less than or equal to that of a comparable non-callable bond because calling a bond moves the final cash flow of the bond earlier in time