A system modeled by Bell-LaPadula has security levels Top Secret, Secret, Confidential, and Unclassified, and categories A, B, C, and D. Specify what type of access (read, write, both, neither) is allowed in each of the following cases:

Case 1: Cleared for (Top Secret, {B, C }) and wants access to a document classified (Secret {B, C, D}) Case 2: Cleared for (Confidential {A, B}) and wants access to a document classified (Confidential {A}) Case 3: Cleared for (Confidential {B, C}) and wants access to a document classified (Secret {C}) Case 4: Cleared for Top Secret ({B, C}) and wants access to a document classified (Confidential {B})