About Question enthuware.oce-ejbd.v6.2.369 :

[jszczepankiewicz]

hmm a serious bug: singletons CAN expose asynchronous methods. Apart from that the first explanation is probably from another question. This question has 4 correct answers.

[admin]

Hi,
The option says, "An asynchronous message destination."
A singleton bean cannot be a message destination. An asynchronous method or asynchronous invokation of a method is not same as a message destination or sending a message to a destination.

So option 1 is wrong and the given explanation is correct.

HTH,
Paul.