Which of the following represents likelihood of occurrence?

$1.$

Likelihood of occurrence is a weakness in an information system, system security procedures, internal controls, or implementation that could be exploited by a threat source.

$2.$

Likelihood of occurrence is a weighted risk factor based on an analysis of the probability that a given threat is capable of exploiting a given vulnerability.

$3.$

Likelihood of occurrence is the magnitude of harm that can be expected to result from the consequences of unauthorized disclosure of information, unauthorized modification of information, unauthorized destruction of information, or loss of information or information system availability.

$4.$

Likelihood of occurrence is any circumstance or event with the potential to adversely impact organizational operations and assets, individuals, other organizations, or the Nation through an information system via unauthorized access, destruction, disclosure, or modification of information, and$/$or denial of service.