A penetration tester must enumerate user accounts and network resources in a highly secured Windows...

CEH v13 explains that when traditional enumeration techniques—such as SMB null sessions—are disabled, attackers often pivot to misconfigured LDAP services that still allow anonymous binding. LDAP anonymous bind, when not properly restricted, exposes directory information such as usernames, organizational units, group memberships, and other metadata. This aligns directly with the scenario, where the tester must avoid triggering alarms while still gathering internal data. LDAP queries generate minimal noise, often blending with normal authentication-related traffic, making them ideal for covert enumeration. Options A and C would require authentication or violate access restrictions, and DNS zone transfers (Option D) rarely succeed because modern DNS servers disable AXFR requests from unauthorized clients. CEH repeatedly stresses the importance of detecting and securing LDAP anonymous bind due to its potential for silent information leakage—making Option B the correct choice.