An LDAP user cannot authenticate against a FortiGate device. Examine the real time debug output shown in the exhibit when the user attempted the authentication; then answer the question below.  〖LDAP用户无法根据FortiGate设备进行身份验证。当用户尝试身份验证时，检查显示的实时调试输出；然后回答下面的问题。〗

　　Based on the output in the exhibit, what can cause this authentication problem?  〖据展示中的输出，什么会导致这种身份验证问题?〗

　　A.User student is not found in the LDAP server.  〖在LDAP服务器中找不到用户学生。〗

　　B.