Assume that we have a T-bill with face value of 1000 $. The maturity date of this bill is Dec. 15th, 2021, today is Jul 20th, 2021. Current price of this bill is 973.14 $. Calculate the yearly discount on this bill assuming Act/Act time convention (take into account possibility of leap year). The yearly discount rate on this bill is:

a.

6.62%

b.

6.12%

c.

6.83%

d.

6.81%