Three identical 180-day $100,000 bank bills have been respectively sold to three investors at a price of $97,500 on 15/1/2022. The After the purchase, these three investors have sold their bills at different yield rate on different dates to realise their capital gain/loss. Please see following table 2 for their investment details

Which of the following statement is correct?

a. We can use sale yield rate to measure the return rate of these three investors .

b. All three investors are having capital gain for their investment.

c. Based on the capital gain/loss figure, Bill is making more profit than other two investors.

d. None of the above statements is correct.