Disaster recovery (DR) is the process of restoring operations to normal after a disaster or disruption. A key aspect of DR is to have a plan in place that outlines the procedures and processes that need to be followed to respond to a disaster and restore operations.

A VPN is a secure tunnel that connects two or more networks over a public network, such as the internet.
VPNs use encryption and authentication protocols to protect the data in transit from unauthorized access, modification, or disclosure. AH is one of the protocols used by IPsec, which is a suite of protocols for securing IP traffic. AH provides integrity, authentication, and anti-replay protection for the entire IP packet, including the header and the payload. AH does not provide payload encryption or sender confidentiality, which are provided by another IPsec protocol called Encapsulating Security Payload (ESP). AH also does not provide multi-factor authentication (MFA), which is a method of verifying the identity of a user or a device by requiring two or more factors, such as something you know, something you have, or something you are. AH does provide sender non-repudiation, which is the assurance that the sender of a message cannot deny sending it, because the message is authenticated with a digital signature or a keyed hash that only the sender can generate. References: CISSP All-in-One Exam Guide, Eighth Edition, Chapter 4: Communication and Network Security, page 215. Official (ISC)2 CISSP CBK Reference, Fifth Edition, Domain 4: Communication and Network Security, page 463.

Mandatory vacations are another type of administrative control that may sound a bit odd at first. Chapter 3 touches on reasons to make sure that employees take their vacations; this has to do with being able to identify fraudulent activities and enable job rotation to take place. -Shon Harris All-in-one CISSP Certification Guide pg 810

JAVA was developed so that the same program could be executed on multiple hardware and operating system platforms, it is not Architecture Specific.
The following answers are incorrect:
Object-oriented. Is not correct because JAVA is object-oriented. It should use the object- oriented programming methodology.
Distributed. Is incorrect because JAVA was developed to be able to be distrubuted, run on multiple computer systems over a network.
Multithreaded. Is incorrect because JAVA is multi-threaded that is calls to subroutines as is the case with object-oriented programming.