Fiber Optic is the most resistant to tapping because Fiber Optic uses a light to transmit the signal. While there are some technologies that will allow to monitor the line passively, it is very difficult to tap into without detection sot this technology would be the
MOST resistent to tapping.
The following answers are in correct:
microwave. Is incorrect because microwave transmissions can be intercepted if in the path of the broadcast without detection.
twisted pair. Is incorrect because it is easy to tap into a twisted pair line.
coaxial cable. Is incorrect because it is easy to tap into a coaxial cable line.

Section: Software Development Security

Acceptability refers to considerations of privacy, invasiveness, and psychological and physical comfort when using the system.
Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the
Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 39