Four Tokens and a Rule to Audit

A factory stamps each inspection token with a letter on one face and a single digit on the other. An auditor must check the rule: "every token with a vowel on its letter face has an even digit on its reverse." Four tokens lie on the bench showing $A$, $M$, $8$, and $5$. Which tokens must the auditor flip over to fully test the rule, turning as few as possible?