A developer wants to achieve the following two behaviors: (1) If a client calls a business method without a transaction context, the container will invoke the bean in an unspecified transaction…

A developer wants to achieve the following two behaviors: (1) If a client calls a business method without a transaction context, the container will invoke the bean in an unspecified transaction context. (2) If a client calls a business method with a transaction context, the container will suspend the association of the transaction context with the current thread before invoking the enterprise bean's business method. Which transaction attribute should be used?