Suppose $A$ noetherian and define
$G(A):=\{M: M$ is an $A$-module reflexive and Ext$^i_A(M,A)=$Ext$^i_A(M^*,A)=0$ for $i\geq1\}$
Why are projective modules contained in this class? Of course if $M$ is projective, then $\mathrm{Ext}^i_A(M,A)=0$. I don't understand why the other conditions hold. Could you tell me why?
(It's not clear to me that we need to suppose $M$ finitely generated.)