In Regards to a CDO Structure, Which of the Below

In regards to a CDO structure, which of the below statements is TRUE?

A) In a CDO structure, there is a collateral manager responsible for managing the portfolio of debt obligations.
B) The portfolio of debt obligations in which the collateral manager invests is referred to as the portfolio.
C) The individual issues held that comprise the collateral are referred to as the collateral liabilities.
D) These debt obligations are referred to as tranches or bond classes. The tranches include: junior tranches, mezzanine tranches, and equity tranche