Arbitrage possibility on T-Bill (question)

Can someone please explain in detail how to solve the following question. It looks simple but I am missing a critical point. Thank you!

A 4 percent Treasury bond has 2.5 years to maturity.

Spot rates are as follows:

(6 month—0.02); (1 year—0.025); (1.5 years—0.03); (2 years—0.04); (2.5 years—0.06)

The note is currently selling for $976.

Determine the arbitrage profit, if any, that is possible.

A)$43.22.

B)$19.22.

C)$37.63.

Discount the cash flows at the spot rates and compare the total value to the price of the bond.

First calculate the arbitrage-free price of the T-Bill: (Note that the spot rates given are annual yields and that you need to divide them by 2 to get the semiannual yields.)

PV =

20 / (1 + 0,01) +

20 / (1 + 0.0125)^2 +

20 / (1 + 0.015)^3 +

20 / (1 + 0.02)^4 +

1,020 / (1+ 0.03)^5

= 956.78

If the note is currently selling for $976.00 the bond is mispriced by + $19.22.

You could explore this arbitrage opportunity by short-selling the T-Bill and using th e proceeds to purchase strips/ zero coupons equivalent to the T-Bill payment structure. You’ll realize an inmediate risk-free profit of $19.22 as the short-selling liability is offset by the future proceeds of the strips / zero coupons.

Best,

Oscar