"Today is 1 July 2021. Joan has a portfolio which consists of two differenttypes of financial instruments (henceforth referred to as instrument A and instrumentB). Joan purchased all instruments on 1 July 2015 tocreate this portfolio and this portfolio is composed of 298 units of instrumentA and 475 units of instrument B.

• Instrument A is a zero-coupon bond with a face value of 100. This bond matures at par. The maturity date is 1 January 2030.
• Instrument B is a Treasury bond with a coupon rate ofj₂= 3.38% p.a. and face value of 100. This bond matures at par. The maturity date is 1 January 2024.

What is the current duration of instrument B? Express your answer interms of years and round your answer to three decimal places.Assume the yield rate isj₂= 3.69%p.a."

a.4.836

b.2.418

c.2.877

d.5.755