The claim that each tranche has an equal claim against the cash flows of the mortgage pools is incorrect. In reality, each tranche of a CMO has a different claim on the cash flows of the mortgage pools. This is because tranches are structured in a way that allows for different levels of risk and return. The structuring of tranches is done in such a way that some tranches receive the principal payments before others. This is done to attract a wide range of investors with different risk appetites. The tranches that receive the principal payments first are considered to be less risky, while those that receive them later are considered to be more risky. Therefore, the claim that each tranche has an equal claim against the cash flows of the mortgage pools is incorrect.

Choice A is incorrect. Collateralized mortgage obligations (CMOs) are indeed securities issued against mortgage pools. This is a fundamental characteristic of CMOs, and Adam and Jack have correctly presented this feature in their presentation.

Choice B is incorrect. The cash flows of the CMOs are allocated to a number of different tranches. This allocation process is known as "tranching," which allows for the creation of securities with different risk profiles from the underlying mortgages. Therefore, this statement by Adam and Jack about CMOs is correct.

Choice D is incorrect. Each tranche of a CMO does indeed have different extension risks and contraction risks due to varying structures, maturities, and prepayment characteristics among tranches within a single CMO issue. Thus, Adam and Jack's explanation on this aspect was accurate.