You have many files in an AWS S3 bucket and you want to make all of them publicly accessible. What is the best approach?

b) Add a policy with * wildcard to make files public

actually u can do it by using method B ...

but what does the Amazon said 

. Sign in to Amazon Web Services and go to your S3 Management Console.

2. Select the bucket from the left. At right, click the Properties button if it’s not already expanded.

3. Go to the Permissions tab and hit the Add Bucket Policy link. (If you’ve previously added a policy, the button will say Edit Bucket Policy instead).