In which of the following level of likelihood is the threat-source highly motivated and sufficiently capable, and controls to prevent the vulnerability from being exercised are ineffective?

A.
Average

B.
Low

C.
High

D.
Medium

Explanation:
Answer option C is correct. Following are the three levels of likelihood:

High: In this level, the threat-source is highly motivated and sufficiently capable, and controls to prevent the vulnerability from being exercised are ineffective. Medium: In this level the threat-source is motivated and capable, but controls are in place that may impede successful exercise of the vulnerability.
Low: In this level, the threat-source lacks motivation or capability, or controls are in place to prevent, or at least significantly impede, the vulnerability from being exercised.