What is the purpose of Email Impersonation Control?

What is the purpose of Email Impersonation Control?

A. To guard against spoofed client’s domains

B. To guard against “whaling” attacks

C. To guard against spoofed government domains
D. To guard against spoofed IP addresses

Reference: https://help.symantec.com/cs/EMAIL_WEB.CLOUD/EMAILSECURITYCLOUD/v122075815_v116575109/Email-Impersonation-Control-Settings?locale=EN_US