A static web site has been hosted on a bucket and is now being accessed by users. One of the web pages javascript section has been changed to access data hosted in another S3 bucket. Now that same web page is no longer loading in the browser. Which of the following can help alleviate the error?

Answer options:

A.Enable versioning for the underlying S3 bucket.
B.Enable Replication so that the objects get replicated to the other bucket.
C.Enable CORS on the bucket containing the data.
D.Change the Bucket policy for the bucket to allow access from the other bucket.

Answer – C
This is given as use case scenarios in the AWS Documentation.
Cross-Origin Resource Sharing: Use-case Scenarios
The following are example scenarios for using CORS.
Scenario 1: Suppose you are hosting a website in an Amazon S3 bucket named website described in Hosting a Static Website on Amazon S3. Your users load the website endpoint http://website.s3-website-us-east-1.amazonaws.com. Now you want to use JavaScript on the webpages stored in this bucket to make authenticated GET and PUT requests against the same bucket by using the Amazon S3 API endpoint for the bucket website.s3.amazonaws.com. A browser would normally block JavaScript from allowing those requests, but with CORS, you can configure your bucket to enable cross-origin requests from website.s3-website-us-east-1.amazonaws.com explicitly.
Scenario 2: Suppose that you want to host a web font from your S3 bucket. Again, browsers require a CORS check (also called a preflight check) for loading web fonts. You would configure the bucket that hosts the web font to allow any origin to make these requests.
Option A is incorrect because Enabling versioning does not solve the problems of accessing form the different buckets. You need to enable CORS on the underlying bucket.
Option B is incorrect because Enabling replication will cost you more as you are maintaining two copies of data.
Option D is incorrect because changing the bucket policy allows access from another bucket, but this will open the whole bucket, not an ideal solution.
For more information on Cross-Origin Resource Sharing, please refer to the below link-
https://docs.aws.amazon.com/AmazonS3/latest/dev/cors.html