  Recently, it was proved by Tikuisis, White and Winter that any faithful trace
on a separable, nuclear $C^\ast$-algebras in the UCT class is quasidiagonal.
Building on their work, we generalise the result, and show that any faithful,
amenable trace on a separable, exact $C^\ast$-algebras in the UCT class is
quasidiagonal. We also prove that any amenable trace on a separable, exact,
quasidiagonal $C^\ast$-algebra in the UCT class is quasidiagonal.
