Final answer:
The general support system's FIPS 199 impact level is either High or Critical.
Step-by-step explanation:
The correct answer is C) High or Critical. When the general support system is a major information system, the system's FIPS 199 impact level is categorized as either High or Critical. FIPS 199 stands for Federal Information Processing Standard, which provides guidelines for categorizing the impact level of an information system based on the potential impact to the organization if the system's confidentiality, integrity, or availability is compromised.