The correct answer is D. 5,400rpm HDD.
A 5,400rpm HDD (Hard Disk Drive) is a type of storage device that uses spinning magnetic disks to store dat a. A 5,400rpm HDD is the least expensive per gigabyte among the options given, as it has a lower rotational speed and performance than other types of HDDs or SSDs (Solid State Drives). A 5,400rpm HDD is suitable for archiving a large number of photos that are not accessed frequently, as it can offer high capacity and reliability at a low cost.
the average cost per gigabyte of a 5,400rpm HDD is around $0.02 to $0.0312, while the average cost per gigabyte of the other options are:
NVMe SSD: $0.10 to $0.1534
SCSI RAID: $0.20 to $0.305
15,000rpm SAS: $0.30 to $0.40
Therefore, a 5,400rpm HDD is the cheapest option among the four.

The cloud model that BEST addresses the company's need is the Community cloud model. A community cloud is a cloud infrastructure in which multiple organizations share resources and services based on common operational and regulatory requirements. The concept of a community cloud is akin to a community garden, where different individuals grow produce on a single piece of shared land1.

In this scenario, running a network cable over a long distance (279ft or 85m) and sharing conduit with a large power cable requires careful consideration of electromagnetic interference (EMI) and the physical distance limitations of the cable type. Fiber optic cables are immune to electromagnetic interference and can support much longer distances than copper-based cables like Cat 5e or Cat 6 without signal degradation. This makes fiber optic the most appropriate choice for this project.
Reference:
CompTIA A+ Core 1 Exam Objectives Section 3.1: Explain basic cable types and their connectors, features, and purposes.
CompTIA A+ Core 1 Exam Objectives Section 2.2: Compare and contrast common networking hardware.

The correct answer is C. DSL.
DSL stands for Digital Subscriber Line, which is a technology that delivers internet over a copper medium, such as a telephone line. DSL uses different frequencies than voice calls, so it can provide both internet and phone service simultaneously. DSL can offer faster speeds than dial-up, but it depends on the distance from the service provider and the quality of the copper line .
The other options are not technologies that deliver internet over a copper medium. ONT stands for Optical Network Terminal, which is a device that converts optical signals from a fiber optic cable to electrical signals for a copper cable or a wireless router. ONT is used for fiber-to-the-home (FTTH) internet service, which delivers internet over a fiber optic medium. SDN stands for Software Defined Networking, which is a technology that allows network administrators to manage and control network resources and traffic using software applications. SDN is not related to the physical medium of internet delivery, but rather to the logical layer of network configuration and optimization. WISP stands for Wireless Internet Service Provider, which is a company that delivers internet over a wireless medium, such as radio waves or microwaves. WISP can provide internet access to rural or remote areas where wired connections are not available or feasible.