Correct Answer: B, CGiven the scenario provided, several factors must be considered to identify the most likely security issues. First, the occurrence of multiple successful MFA log-ins from geographically disparate locations within a very short time frame indicates a situation of 'impossible geo-velocity' — it is physically impossible for the same user to log in from the United States and Russia within minutes. Second, frequent successful MFA log-ins suggest that the user might be unknowingly giving access, potentially due to push phishing, where the victim is tricked into approving fraudulent MFA requests. Therefore, the two most likely occurrences are impossible geo-velocity and push phishing.