单选题 In the following essay, each blank has four choices. Choose the best answer and write down on the answer sheet.
In security, an (71) is a form of possible loss or harm in a computing system; examples of exposures are unauthorized disclosure of data, modification of data, or (72) of legitimate access to computing. A vulnerability is a weakness in the security system that might be exploited to cause loss or harm. A human who exploits a vulnerability perpetrates an attack on the system. Threats to computing systems are circumstances that have the potential to cause loss or harm; human attacks are examples of threats, as are natural disasters, inadvertent human errors, and internal hardware or software (73) . Finally, a control is a protective measure an action, a device, a procedure, or a technique - that reduces a vulnerability. The major (74) of computing systems are hardware, software, and data. There are four kinds of threats to the security of a computing system: interruption, interception, modification, and (75) . The four threats all exploit vulnerabilities of the assets in computing systems.