Add an S3 bucket policy that grants public read access and verify S3 Block Public Access is not blocking it is the correct option because the S3 website endpoint requires anonymous s3:GetObject permissions on the objects to serve the index document instead of returning HTTP 403. If the Route 53 alias points to the S3 website endpoint but objects are not publicly readable or Block Public Access is preventing public policies the browser will see 403.

You should apply a bucket policy that allows s3:GetObject on the bucket object ARN pattern and then confirm that Block Public Access settings at the bucket or account level are not blocking those public policies. Granting public read on objects is the usual fix for static website hosting when the DNS and website configuration are already correct.

Create an IAM role is incorrect because IAM roles grant permissions to AWS principals and services and they do not grant anonymous public access for website visitors.

Enable CORS on the bucket is incorrect because CORS controls cross origin requests and does not change the object read permissions that cause a 403 error.

Turn on default server-side encryption for the bucket is incorrect because encryption affects data at rest and does not grant or change public read permissions so it will not resolve a 403 response.

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