As a presenter, you may accept or reject the raised hand request made by the attendee. To grant privileges: 

1. In the Attendees List window, click (use left mouse button) on the name of the attendee.
2. A context sensitive menu containing Transfer control option pops up.
3. Click 'Transfer Control' option.
4. Privilege assignment confers audio (conversing), annotation and file (presentations, document and image) upload rights on the attendee. An appropriate icon appears besides the name of the attendee in the attendees list window.
5. Similarly you can also assign video privileges to your attendees.