Moderators use polls for many different reasons.
It might be to give you opportunities to participate and provide feedback. Or to start a discussion. It might also be to see how well you understood what they presented.
After a moderator starts a poll you are asked to make a choice. The choices disappear so they don't block anything on the main stage. Select Polling to open the choices again. Select your choice.
Screen readers only announce the numbers for each option. Ask your moderator what each number represents.
You only see the choice you make. Moderators see an overview of the choices made. They can also see the specific choice you and other attendees make. They can also see who hasn't responded.
Moderators might choose to show you the overall responses but you never see how anyone else has responded.