a. A snapshot is a point-in-time copy of data that does not depend on other files. A differential backup backs up files that have changed since the last full backup and does not require any other file to restore data.

Reference:
https://www.csoonline.com/article/3191531/securing-risky-network-ports.html

Explanation
To calculate the minimum number of disks needed for this application, we need to consider the RAID levels and their disk requirements. RAID 1 requires a minimum of two disks and provides mirroring, which means that data is duplicated on both disks. RAID 5 requires a minimum of three disks and provides striping with parity, which means that data is distributed across all disks with one disk storing parity information for error correction. RAID 5 can tolerate one disk failure without losing data. To create a 10GB RAID 1 array for log files, we need two 10GB disks. To create a 20GB RAID 5 array for data files, we need four 10GB disks (three for data and one for parity). To create a 20GB RAID 5 array for the operating system, we need another four
10GB disks (three for data and one for parity). Therefore, the total number of disks needed is 2 + 4 + 4 = 10.
However, since we can use different RAID levels for different partitions on the same disk, we can optimize the disk usage by using only eight disks as follows: Disk 1: 10GB RAID 1 (log files) + 10GB RAID 5 (data files) Disk 2: 10GB RAID 1 (log files) + 10GB RAID 5 (data files) Disk 3: 10GB RAID 5 (data files) + 10GB RAID 5 (OS) Disk 4: 10GB RAID 5 (data files) + 10GB RAID 5 (OS) Disk 5: 10GB RAID 5 (parity for data files) + 10GB RAID 5 (OS) Disk 6: 10GB RAID 5 (OS) + unused space Disk 7: 10GB RAID 5 (parity for OS)
+ unused space Disk 8: unused space References: https://en.wikipedia.org/wiki/Standard_RAID_levels

Overprovisioning is a situation where the allocated resources for a virtual machine exceed the available resources of the physical host. In this case, the storage allocated for Server 1 and Server 2 on VM01 is 8TB and 10TB respectively, which adds up to 18TB. However, the storage available on the VM01 host is only 16TB, which means there is a 2TB deficit. This can cause performance issues and errors for the virtual machines.
References:
CompTIA Server+ Certification Exam Objectives1, page 8
Server Management: Server Hardware Installation and Management, Module 2, Lesson 5

A piece of console furniture called a "crash cart" refers to a mobile server room cart equipped with a secured laptop that is used to provide a direct connection to malfunctioning servers and computers for restoration of crashes. - Not the answer.
4U would require at least 4 admin so not the answer....
Server lifts are used to raise equipment to installation level in a frame (cabinet or rack) or to remove equipment from a frame. Server lifts should only be used on level floors strong enough to support lift and load... Using a lift may be slower than maneuvering by hand; but if worker or equipment safety (usually because of weight) is a factor; using a lift is required.
https://www.idmworks.com/industry-analysis/data-center-server-lift/