You are the new portfolio manager for a large companys pension plan.The plan hasto make payments of $5B in a year (t=1), $6B in 2 years (t=2), $7B in 3 years (t=3),and $2B in 4 years (t=4).The yield curve is at at 4%.What is the duration of theseliabilities?

A.2.27 years

B.1.42 years

C.3.13 years

D.2.88 years

E.1.76 years