The Opale fund issues two classes of units: class A, redeemable at the holder's option, and class B, with no redemption option. On liquidation, class A ranks last, at the same rank as class B, and no other class is more subordinated (case facts). A colleague argues that class A's redemption option makes it less subordinated than class B and therefore rules out the exception. Which answer is consistent with the explanation the Committee gave in 2009 (background, not a rule)?