To answer this question, the user needs to have knowledge of VSAM (Virtual Storage Access Method) and the process of VSAM REORG.

The correct answer is:

D. All of the above

Explanation:

The process of VSAM REORG involves the following steps:

A. Copy the data of VSAM file which has to be REORG into another dataset: This step involves backing up the data in the VSAM file to another dataset before the REORG process can begin. This ensures that the data is not lost in case the REORG process fails.

B. Delete the current VSAM dataset: Once the backup is complete and verified, the original VSAM dataset can be deleted.

C. Define the VSAM dataset: After the original dataset has been deleted, a new VSAM dataset can be defined with the same name and attributes as the original dataset.

Therefore, all of the options listed above are correct steps that are involved in the process of VSAM REORG.