The correct answer is D. This option specifies creating a single S3 bucket policy that lists multiple aws:SourceVpce conditions using StringNotEquals for all relevant VPC endpoint IDs. This approach is the closest to ensuring that users can only access the S3 bucket through specified VPC endpoints, as it explicitly states the acceptable VPC endpoints. Using StringNotEquals helps in denying access if the requests come from any endpoints not listed. The other options either do not comprehensively cover all VPC endpoints or are not appropriately configured to meet the requirements.