Universal Container’s Sales Ops admin was trying to merge two duplicate accounts within the system. One of the accounts was a business account and the other one was a person account. But the merging kept on failing. What is the possible reason for this?

Answer options:

A.You cannot merge business and person accounts together
B.Duplicate account’s rules are not set
C.Matching rules are not active
D.No permission is given to Sales Ops to merge accounts

Correct Answer: A 
You cannot merge business and person accounts together in Salesforce. You can either merge business accounts alone or person accounts alone. 
Other options are incorrect because the issue is related to having one business account and one person account. 
Reference: 

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