Answer:
Note: CA here in the answer means Certificate Authority
Segmenting the role of the Root CA and Issuing CA to provide a secure configuration.
Keeping the Root CA offline, thus allowing the private key of the Root CA to be more secure.
Allowing multiple deployment of Issuing CAs at different geographical locations.
Greater control of Issuing CAs at different security levels.
Less management and implementation than a three-tier design.
Greater security than a single tier design.
More scalability for the security environment by deploying more Issuing CA.
