An IS auditor is conducting a review of a data center. An observation that could indicate an access control issue is muddy footprints directly inside the emergency exit. Access control is a process that ensures that only authorized entities or individuals can access or use an information system or resource, and prevents unauthorized access or use. Access control can be implemented using various methods or mechanisms, such as physical, logical, administrative, etc. Muddy footprints directly inside the emergency exit could indicate an access control issue, as they could suggest that someone has entered the data center through the emergency exit without proper authorization or authentication, and potentially compromised the security or integrity of the data center. Security cameras deployed outside main entrance is not an observation that could indicate an access control issue, but rather a control that could enhance access control, as security cameras are devices that capture and record video footage of the surroundings, and can help monitor and deter unauthorized access or activity. Antistatic mats deployed at the computer room entrance is not an observation that could indicate an access control issue, but rather a control that could prevent static electricity damage, as antistatic mats are devices that dissipate or reduce static charges from people or objects, and can help protect electronic equipment from electrostatic discharge (ESD). Fencing around facility is two meters high is not an observation that could indicate an access control issue, but rather a control that could improve physical security, as fencing is a barrier that encloses or surrounds an area, and can help prevent unauthorized entry or intrusion.