Choice "C" is correct. Application programmers should not be allowed to enter data in production systems nor should they have unrestricted and uncontrolled access to application program change management systems. An application programmer is the person responsible for writing and/or maintaining application programs and should not be responsible for also controlling or handling data.
Choice "b" is incorrect. Network maintenance and wireless access are both responsibilities of the Network Administrator.
Choice "d" is incorrect. Data entry and antivirus management can safely be assigned to the same person, as they are not incompatible functions.
Choice "a" is incorrect. Data entry and quality assurance can safely be assigned to the same person, as they are not incompatible functions.