Explanation
The most efficient subnet address for a network that will have no more than 30 available IP addresses is
255.255.255.224. This subnet mask corresponds to a /27 prefix length, which means that 27 bits are used for the network portion and 5 bits are used for the host portion of an IP address. With 5 bits for hosts, there are
2^5 - 2 = 30 possible host addresses per subnet, which meets the requirement. The other options are either too large or too small for the network size. Reference: https://www.ibm.com/cloud/learn/subnet-mask

Explanation
Few people are expected to use the database at the same time and users don't need to customize the design of the database.

Explanation
The bootloader configuration file is used to specify which kernel version and options to use when booting the system. The first kernel stanza in the file is the default one that is loaded automatically. By editing this stanza and changing it to point to the last known-good kernel files, the administrator can boot the system with a working kernel and avoid any compatibility issues with the new kernel update. Verified References: [How To Change The Linux Kernel Version]

Explanation
A database server is a server that hosts a database management system (DBMS) that stores, organizes, and manipulates data. A database server is suitable for housing customer sales records, as it can provide fast and secure access, query and analysis capabilities, backup and recovery options, and scalability and performance optimization. Some examples of database servers are Microsoft SQL Server, Oracle Database, MySQL, and PostgreSQL. Verified References: [What is a Database Server?]

Explanation
PowerShell is a scripting language and a command-line shell that uses commands that start with sec- to perform security-related tasks. For example, sec-edit is a command that edits security policies, sec-logon is a command that manages logon sessions, and sec-policy is a command that applies security templates. Verified References: [PowerShell security commands], [Security policy]