The correct answer is A - Unsecured wireless access points.
WGU Cybersecurity Architecture and Engineering (KFO1 / D488) explains that unauthorized logins to a WLAN often indicate poorly secured wireless access points, such as those lacking strong encryption (e.g., WPA2/WPA3), not using strong passwords, or having open access without authentication. This vulnerability can allow attackers to access internal systems and sensitive data.
Up-to-date anti-malware software (B), a strong password policy (C), and regular security training (D) are good security practices but do not directly explain unauthorized WLAN access.
Reference Extract from Study Guide:
"Unauthorized wireless access often results from unsecured wireless configurations, including weak encryption, open networks, or default credentials, posing significant risks to organizational assets."
- WGU Cybersecurity Architecture and Engineering (KFO1 / D488), Wireless Security Concepts