Please answer the following:

On December 26, 2017, the Wall Street Journal published an article entitled Investors Diving Into Risky Bank Bonds. The article describes contingent convertible bonds (or CoCos). Based on information given in the article, the primer from the Bank for International Settlements, and any other resources you might find, answer the following questions:

* A. What are contingent convertible securities?

* B. Why might banks be interested in issuing them?

* C. Why might investors be willing to buy them?

* D. Why might regulators encourage their use?

* E. How does this financial instrument fit with the two key principles recognized in the teaching note from the course pack on The Design of Securities?