Yahoo answer can be mentioned as best answer by the owner of the question, and other viewers can do by providing thumbs up to your answer.
The owner of the qustion can choose or the people who are all viewing that question can put vote for the answer to be a best one.
Mostly if the question asker is active then he would choose the best answer, sometimes voters can choose well if the voters choose the best answer then it would be open for voting unlike if the question starter chose the best answer the question will be resolved.
If the creator of the question does not select the best answer within the specified time, than it becomes open for other members to vote. The answer that gets the most number of votes wins. Of late, I don't really visit yahoo answers, because those points are just for you to feel good, the same thing can be used in other sites to earn cash
Well, most of the times I have seen the questions starter selects the best answer ! But members also have the feature to vote if its not selected over a particular time period. - Digital -
best answer is selected by 2 ways 1)user who have opened question 2)by voting of other users Good luck
That is probably my favorite site to get good answers. I just started using yahoo because of answers.
This is the correct answer. Many others are giving you a partial one. As he said, the creator picks the best answer, but if he failed to do it within a certain amount of time, the community can vote for the best answer.