In a computer system, independent checks on performance are often unnecessary because a procedure is performed by a computer program. Similarly, computer programs rather than independent staff often prepare reports that compare data and assets for accountability purposes. As a result, which of the following controls in a computer system becomes important to the auditor:

a. Equipment controls to ensure that hardware does not malfunction

b. Backup and recovery controls

c. Controls over the development, maintenance, and modification of program code

d. Personnel controls that ensure only high-quality staff are hired