Explanation
Adjusting the lens is the best solution to improve image quality in a projector. The lens can become misaligned over time or during transportation, causing the image to appear fuzzy.

A driver is a software component that enables the communication between the operating system and a hardware device, such as a printer. If the driver is corrupted, outdated, or incompatible, the printer may not function properly and produce illegible prints or symbols. The driver can be reinstalled or updated to fix the issue. The fuser, the access control list, and the malware are not related to this issue.

Installing an M.2 SSD will improve a workstation's overall response time for frequently used applications and data without removing the current hard drive. M.2 drives are faster and more efficient than traditional hard drives, making them a good option for increasing overall performance. Reference: CompTIA A+ Certification Exam Core 1 Exam Objectives - 1.5 Given a scenario, configure storage devices and use appropriate media

Cat 5 cable is limited to a maximum data transfer rate of 100Mbps, while Cat 5e, Cat 6, and Cat 6a cables support Gigabit Ethernet (1000Mbps) and higher speeds. Even though the LAN card is capable of Gigabit speeds, it cannot achieve that speed when using a Cat 5 cable. Upgrading to a Cat 5e or higher cable would allow the computer to achieve Gigabit speeds. Reference: CompTIA A+ Certification Exam: Core 1 - Page 196

Explanation
Optical fiber is the type of cable that should be used to terminate ST connectors on each end. ST connectors are commonly used for fiber optic cables, which transmit data using light pulses. Coaxial, shielded twisted pair, and HDMI are not types of cables that use ST connectors, but different types of connectors and transmission methods.