Universal Container’s Salesforce Admin is going on leave and wants to delegate some administrative duties to one of the customer portal users. How can the delegated administrator be enabled for the customer portal user?

Answer options:

A.Go to setup, search for security controls, then delegated administration
B.Customer Portal user cannot have delegated administrative duties
C.Enable the delegated administrator through the customer portal user record
D.Enable the delegated administrator through the community

Correct Answer: B 
Customer Portal users cannot have delegated administrative duties. Only Salesforce users within your organization can have the delegated administrative duties assigned to them. 
Options A, C, and D are incorrect because Customer Portal users cannot have delegated administrative duties. 
Reference: 

https://help.salesforce.com/articleView?id=delegating_user_administration.htm&type=5