A company wishes to increase security at the employee entrance. Which of the following technologies would be the most useful?

a digital ink pen

Automated Fingerprint Verification

RFID

Electronic Paper Display

The most useful would have to be the Automated Fingerprint Verification, since it would only work with a few peoples fingerprints, or well, whomever it was designed to work for.

A digital ink pen? That's out by a long shot, RFID is Radio Frequency Id. Meaning, if someone were to take the item that is using the Radio Frequency, they would be able to get in easily. Electronic Paper Display is the same way. If you take it from the person that is supposed to have it, you can easily get in.