Which of the following access control models are used in the commercial sector? Each correct answer represents a complete solution. Choose two.

The Biba model is an integrity-focused access control model that prevents subjects from writing to objects of lower integrity (no write down) and reading from objects of higher integrity (no read up), making it highly suitable for commercial environments where data integrity is paramount.

The Clark-Biba model is not a standard or commonly recognized standalone access control model; it appears to be a conflation of the two distinct models.

The Clark-Wilson model is an integrity model that uses well-formed transactions and separation of duties to maintain data integrity, ensuring that data is only modified in authorized ways. This makes it particularly relevant for commercial applications requiring high assurance of data accuracy, such as banking and accounting systems.

The Bell-LaPadula model is primarily a confidentiality-focused access control model, preventing unauthorized information flows from higher to lower classification levels. While important, its emphasis on confidentiality makes it more prevalent in military and government sectors than in the typical commercial sector where data integrity often takes precedence.