To enable SNMP v2c on a managed FortiSwitch, the essential requirement involves configuring the SNMP agent and community strings:

Configure SNMP Agent and Communities (D):

SNMP Agent:Activating the SNMP agent on FortiSwitch allows it to respond to SNMP requests.

Community Strings:SNMP v2c uses community strings for authentication. These strings function as passwords to grant read-only or read-write access to the SNMP data.

Understanding Other Options:

Create an SNMP user (A)is necessary for SNMP v3, not v2c, as it involves user-based authentication and encryption.

Specify an SNMP host (B)is typically a part of SNMP configuration but not a requirement just to enable SNMP.

Enable SNMP v3 (C)is not related to enabling SNMP v2c.

References:For detailed instructions on configuring SNMP on FortiSwitch, you can refer to the SNMP configuration section in the FortiSwitch administration guide available on:Fortinet Product Documentation