The correct answer is C, Amazon FSx for Windows File Server. This service is specifically designed to provide fully managed, highly reliable, and scalable file storage that is accessible over the Server Message Block (SMB) protocol, which is commonly used with Microsoft Windows operating systems. Unlike Amazon S3, which is an object storage service, Amazon EFS, which uses the NFS protocol, and Amazon EBS, which is a block storage service using iSCSI, Amazon FSx for Windows File Server is the only option that meets the criteria of being accessible over SMB and being designed for Windows-based applications and workloads.