Final answer:
To grant members of a role permission to view query execution plans, grant the SHOWPLAN permission.
Step-by-step explanation:
To grant members of a role permission to view query execution plans, you should grant the SHOWPLAN permission. This permission allows users to view the execution plan of a query, which includes information about how the database engine will execute the query. By granting this permission, members of the role will be able to analyze and optimize query performance.