Answer:
a. It is a weighted average of time period where the weights are the percentage of the bond's value coming from that period.
c. It is used to assess a bond's credit risk.
d. The duration of a zero-coupon bond is equal to its time to maturity.
Step-by-step explanation:
Duration of a bond is a measure of relative change in price with change in interest rate. A bond is weighted average of times until fixed cash flows are received. The duration of a zero coupon bond is always equal to its time to maturity. The cash flows for these types of bonds are positive and fixed. Duration is also used to assess risk exposure and credit risk of a bond.