Which new feature did HP introduce on its security labels in late 2011?

A.
Quick Response (QR) code

B.
OK and ! that move in opposite direction when the box is tilted front to back

C.
invisible ink to add another layer of security

D.
RFID features to scan large batches at a time

Explanation:
Reference: http://www.aridvalok.com/articles/how-to-identify-original-hp-toner.html