Information flow metrics is used to slow down the propagation of viruses. Given that Anne: VA = 4; Bill: VB = 2, and Cathy: VC = 3. Anne creates program P containing virus. Cathy executes P that...

Information flow metrics is used to slow down the propagation of viruses. Given that Anne: VA = 4; Bill: VB = 2, and Cathy: VC = 3. Anne creates program P containing virus. Cathy executes P that writes to Q. Can Bill execute Q (assuming Q will produce R)? Who may execute Q? Who may execute R?