Encryption is the correct choice because it provides a method to protect the confidentiality and integrity of data by transforming it into a non-readable form for unauthorized users. This is particularly important for data classified as 'Critical', as unauthorized access or alteration could lead to severe impacts on business operations. While geographic restrictions, hashing, and masking provide protection mechanisms, they either do not fulfill both confidentiality and integrity needs as encryption does, or are more suited for different data protection aspects rather than for 'Critical' data that requires strong protection against unauthorized access and tampering.