All you need to make a meter work is a left and a right option. Accepted Answers are not required. The audience will have to type in the options exactly as they are shown in order for their vote to be counted.
For instance, using the example above, the audience will have to type in either #NYC or #LA to vote. If you did include accepted answers, the audience might be able to type things like New York, Los Angeles, and #NY and those would count towards the tally, depending on what options you chose to list in Accepted Answers.