Port security is a feature that allows network administrators to limit the number of devices that can connect to a switch port, based on the MAC address of the device. This can prevent unauthorized physical connectivity by blocking any device that is not on the allowed list or exceeding the maximum number of devices per port. Port security can also trigger an action, such as shutting down the port or sending an alert, when a violation occurs. Reference: CompTIA Network+ N10-008 Cert Guide - O'Reilly Media, Chapter 14: Securing a Basic Network, page 512

Explanation
SNMP (Simple Network Management Protocol) is a protocol that allows network devices to communicate with a management server. By using SNMP, the company can set up an SNMP agent on each sensor, which will report its temperature readings to an existing collector server. This will enable the company to monitor the temperatures of all their sensors in real-time without the need for manual checks. Additionally, SNMP's scalability means that even if the company adds more rooms or sensors, the existing system can be easily expanded to accommodate them.

A wireless controller is used to manage a corporate WLAN, providing centralized management and configuration of access points. Reference: CompTIA Network+ Certification Study Guide, Chapter 8: Wireless Networks.

Explanation
Band-steering is a feature that allows an AP to steer dual-band capable clients to the less congested 5GHz frequency, leaving the 2.4GHz frequency for legacy clients. Without band-steering, the AP may have more clients competing for the same channel on the 2.4GHz frequency, resulting in high latency and airtime contention.
References:
According to the CompTIA Network+ Certification Exam Objectives, one of the topics covered in the exam is "Given a scenario, use appropriate wireless technologies and configurations". One of the subtopics is "Band steering" 1.
According to the PoliFi: Airtime Policy Enforcement for WiFi paper, "Band steering allows the access point to disable the 2.4 GHz band from probing the client device, so it responds only to the 5 GHz band, reducing the congestion on the 2.4 GHz band while taking advantage of the faster 5GHz band to improve user's network experience." 2.
According to the Aruba Air Slice Tech Brief, "Air Slice minimizes airtime contention and efficiently groups Wi-Fi 6 and non-Wi-Fi 6 client devices to guarantee bit rate, and provide bounded latency and jitter simultaneously." 3.