Waiting Room

Hopefully I can find an answer here.  As host, I (or my cohost) admit admit every  participant into my meeting from the waiting room.  To increase security, I would like to ask the person  who is waiting a question, and then  have them be able to respond to me.  I understand that this is  possible in my discussion with other  hosts.  However, I have tried it in my meeting and this is what happens:  I can indeed chat with a person who is in the waiting room, but THEY CANNOT REPLY to me.  What setting will enable me, as host, to allow those in the waiting room to respond to my question to them?  Thanks in advance!!