What advice should be given to him to enhance the security?

A user is creating multiple IAM users. What advice should be given to him to enhance the security?

A.
Grant least privileges to the individual user

B.
Grant all higher privileges to the group

C.
Grant less privileges for user, but higher privileges for the group

D.
Grant more privileges to the user, but least privileges to the group

Explanation:
It is a recommended rule that the root user should grant the least privileges to the IAM user or the group. The higher the
privileges, the more problems it can create.
http://docs.aws.amazon.com/IAM/latest/UserGuide/IAMBestPractices.html