The correct answer is Amazon S3 Standard-Infrequent Access (S3 Standard-IA). This storage class offers high durability, availability, and performance object storage for data that is accessed less frequently, but requires rapid access when needed. It provides a lower cost than S3 Standard, making it ideal for long-term storage, backups, and as a data store for disaster recovery files. The incorrect answers were chosen to be subtly misleading; S3 Glacier and S3 Glacier Deep Archive offer low-cost solutions for archived data that is accessed very infrequently and with a delay in retrieval time, which does not meet the client's need for quick access. S3 One Zone-IA offers a cost-saving compared to S3 Standard-IA, but stores data in a single zone, which subjects it to a higher risk of data loss if that zone is compromised; hence, it is not recommended for critical data that needs to be highly available.