Which of the following security models characterizes the rights of each subject with respect to every object in the computer system?

The Clark-Wilson model is an integrity model focused on commercial applications, emphasizing well-formed transactions and separation of duties to maintain data integrity, not directly characterizing subject-object rights for all system objects.

The Bell-LaPadula model is a confidentiality-focused model that prevents unauthorized information flow from higher security levels to lower ones (no read up, no write down), but it's not a general model for characterizing all subject-object rights.

The Biba model is an integrity-focused model that prevents information flow from lower integrity levels to higher ones (no read down, no write up), complementing Bell-LaPadula, but it's also not a general model for all subject-object rights.

An access matrix is a conceptual security model that explicitly defines the permissions or rights that each subject (e.g., user, process) has with respect to every object (e.g., file, printer, memory segment) in a computer system. It is a fundamental representation of discretionary access control, where each entry [Subject, Object] in the matrix specifies the authorized operations.