The correct answer is B.
OBJ-2.1: Installing a jumpbox as a single point of entry for the administration of servers within the cloud is the best choice for this requirement. The jumpbox only runs the necessary administrative port and protocol (typically SSH). Administrators connect to the jumpbox then use the jumpbox to connect to the admin interface on the application server. The application server’s admin interface has a single entry in its ACL (the jumpbox) and denies any other hosts’ connection attempts. A bastion host is a special-purpose computer on a network specifically designed and configured to withstand attacks. The computer generally hosts a single application. For example, a proxy server and all other services are removed or limited to reduce the threat to the computer. An airgap system is a network or single host computer with unique security requirements that may physically be separated from any other network. Physical separation would prevent a system from accessing the remote administration interface directly and require an airgap system to reach the private cloud.