已知创建/usr/local/nagios/etc/objects/services.cfg文件来定义服务，在主配置文件nagios.cfg中引用的方法为（）

A.object_cache_file=/usr/local/nagios/etc/objects/services.cfg
B.cfg_file=/usr/local/nagios/etc/objects/services.cfg
C.log_file=/usr/local/nagios/etc/objects/services.cfg
D.resource_file=/usr/local/nagios/etc/objects/services.cfg