What is a difference between host-based intrusion detection systems (HIDS) and network-based intrusion detection systems (NIDS)?

A . NIDS are usually a more expensive solution to implement compared to HID
C . Attempts to install Trojans or backdoors cannot be monitored by a HIDS whereas NIDS can monitor and stop such intrusion events.
D . NIDS are standalone hardware appliances that include network intrusion detection capabilities whereas HIDS consist of software agents installed on individual computers within the system.
E . HIDS requires less administration and training compared to NID

Answer: C