Which of the following(s) is/are likely not (a) reason(s) for changes in the required rate of return of a bond?

A. The economy experiences a downturn or a financial crisis.

B. The management wants to develop a new product within the next 10 years. The feasibility study, currently being implemented, shows positive preliminary signals.

C. The issuers credit quality increases.

D. All of the other answers.

*** D is not the right answer