Which of the following is true?

Group of answer choices

a.For a company that starts with a poor credit rating, default probability in a year tends to decrease with time because the firm's financial health will definitely improve in the future.

b.For a company that starts with a good credit rating, default probability in a year tends to be a decreasing function of time.

c.For a company that starts with a poor credit rating, default probability in a year tends to decrease with time because the firm's financial health is likely to have improved if the firm survives this period.

d.For a company that starts with a good credit rating, default probability in a year tends to be an increasing function of time since the more time that elapses, the lower chance that the firm's financial health will decline.