1U stands for one unit and it is a standard unit of measurement for rack-mounted servers. It is equal to 1.75 inches (4.45 cm) in height. A 42U rack can accommodate 42 1U servers or a combination of servers with different unit sizes. Therefore, the unit size per server should be 1U if there are 19 1U servers in a 42U rack. Reference: https://www.comptia.org/training/resources/exam-objectives/comptia-server-sk0-005-exam-objectives (Objective 1.2)

GPT (GUID Partition Table) is a partitioning scheme that allows creating partitions on large hard drives (more than 2 TB). It supports up to 128 partitions per drive and uses 64-bit addresses to locate them. MBR (Master Boot Record) is an older partitioning scheme that has limitations on the size and number of partitions (up to 4 primary partitions or 3 primary and 1 extended partition per drive). To provision a new 4 TB drive, the technician should partition it using GPT. Verified References: [GPT], [MBR]

This is the most secure method to access servers located in remote branch offices because MFA stands for multi-factor authentication, which requires users to provide more than one piece of evidence to prove their identity. An out-of-band solution means that one of the factors is delivered through a separate channel, such as a phone call, a text message, or an email. This adds an extra layer of security and prevents unauthorized access even if a password is compromised.References:https://docs.microsoft.com/en-us/azure/active-directory
/authentication/concept-mfa-howitworks

Cloud software licensing refers to the process of managing and storing software licenses in the cloud. The benefits of cloud software licensing models are vast. The main and most attractive benefit has to do with the ease of use for software vendors and the ability to provide customizable cloud software license management based on customer needs and desires1. Cloud-based licensing gives software developers and vendors the opportunity to deliver software easily and quickly and gives customers full control over their licenses, their analytics, and more1. Cloud based licensing gives software sellers the ability to add subscription models to their roster of services1. Subscription models are one of the most popular forms of licensing today1. Users sign up for a subscription (often based on various options and levels of use, features, etc.) and receive their licenses instantly1. Reference: 1 Everything You Need to Know about Cloud Licensing | Thales