What is the first step in an Anti-Virus Scan-on-first-read Operation?

A.
The file is opened for the client

B.
Client issues a read request for the file saved on the backend storage

C.
The Anti-Virus agent scan the file and take corrective action

D.
VNX/VNXe compares file access time and reference time, and trigger a scan request to the AV engine if nessary