You should have enough posts to be able to post a poll. Try starting a new thread.
Once you've finished writing the test, but before you hit submit, scroll down below the submit button. There should be an area underneath the thread subscriptions box for creating a poll. Tick the box next to Yes, post a poll with this thread. Select the number of options (choices) that you would like to include in the poll (up to 12). Then hit the Submit button. Your new thread will be posted but instead of being directed to your post, you will be directed to a page where you can create your poll.