Application consistent backup is a method of backing up data that ensures the integrity and consistency of the application state. It involves notifying the application to flush its data from memory to disk and quiescing any write operations before taking a snapshot of the data. If the databases were not backed up to be application consistent, they might contain incomplete or corrupted data that cannot be restored properly.
References:
CompTIA Server+ Certification Exam Objectives1, page 12
What is Application Consistent Backup and How to Achieve It2
Application-Consistent Backups3

Explanation
A template is a preconfigured virtual machine image that can be used to create new virtual machines quickly and easily. A template can include the operating system, applications, settings, and data that are required for a specific purpose or role. A type 1 hypervisor is a virtualization technology that runs directly on bare metal hardware, without requiring an underlying operating system. A type 1 hypervisor can provide better performance, security, and isolation for virtual machines than a type 2 hypervisor, which runs on top of an operating system. Verified References: [Template], [Type 1 hypervisor]

Explanation
The subnet mask is most likely containing an error that prevents the application server from communicating with the newly installed database server. The subnet mask is a binary number that defines how many bits of an IP address are used for the network portion and how many bits are used for the host portion. The subnet mask determines which devices belong to the same network or subnet and can communicate directly with each other without routing or switching devices. The subnet mask of the database server is 255.255.O.O, which means that all 32 bits of its IP address are used for the network portion and none for the host portion, which is invalid and makes it unreachable by any other device on any network or subnet. The subnet mask of the application server is 255.O.O.O, which means that only 8 bits of its IP address are used for the network portion and 24 bits are used for the host portion, which is also uncommon and makes it incompatible with most networks or subnets. References: [CompTIA Server+ Certification Exam Objectives], Domain 4.0: Networking, Objective
4.1: Given a scenario, configure network settings for servers.