Refer to the Following Configuration Snippet of a Cisco IOS

Refer to the following configuration snippet of a Cisco IOS router: snmp-server community private RO 60 snmp-server host 192.168.15.4 private access-list 60deny 192.168.12.0 255.255.240.0 access-list 60 permit snmp 192.168.15.4 The network management system (NMS) IP address is 192.168.15.4, and it is receiving SNMP traps from the router, but it is not able to poll the router. Why is the NMS unable to poll the router?

A) SNMP is not enabled on the router.
B) No public community string is configured.
C) The access-list is denying SNMP access from the NMS.
D) The NMS requires a read-write community string.