Monitoring electromagnetic pulse emanations from PCs and CRTs provides a hacker with that significant advantage?

Monitoring electromagnetic pulse emanations from PCs and CRTs provides a hacker with that
significant advantage?

A.
Defeat the TEMPEST safeguard

B.
Bypass the system security application.

C.
Gain system information without trespassing

D.
Undetectable active monitoring.

Explanation:
Tempest equipment is implemented to prevent intruders from picking up information
through the airwaves with listening devices. – Shon Harris All-in-one CISSP Certification Guide pg
192. In Harris’s other book CISSP PASSPORT, she talks about tempest in terms of spy movies
and how a van outside is listening or monitoring to the activities of someone. This lends credence
to the answer of C (trespassing) but I think D is more correct. In that all the listener must do is
listen to the RF. Use your best judgment based on experience and knowledge.