Businesses Vary as to the Amount of Security They Require

Businesses vary as to the amount of security they require or can afford in order to protect their computer files. A company that sells a complete line of firewalls, from a no-frills version to one that uses complex retinal scans, would most likely employ which promotional element to effectively promote its product to businesses?

A) personal selling
B) advertising
C) sales promotion
D) public relations
E) social media