When you put objects in Amazon S3, what is the indication that an object was successfully stored?

A. A HTTP 200 result code and MD5 checksum, taken together, indicate that the operation was successful.
B. Amazon S3 is engineered for 99.999999999% durability. Therefore there is no need to confirm that data was inserted.
C. A success code is inserted into the S3 object metadata.
D. Each S3 account has a special bucket named _s3_logs. Success codes are written to this bucket with a timestamp and checksum.