The objective that an evil twin achieves is log-in credentials. An evil twin is a type of rogue access point that mimics a legitimate wireless network by using the same SSID, encryption, and authentication methods. An evil twin can trick unsuspecting users into connecting to it instead of the real network, and then capture their log-in credentials or other sensitive dat a. An evil twin can also perform man-in-the-middle attacks, redirecting or modifying the user's traffic. Reference: CompTIA Network+ N10-008 Certification Study Guide, page 358; The Official CompTIA Network+ Student Guide (Exam N10-008), page 14-1.

Phishing is a type of social engineering attack that uses email, phone, SMS, or other forms of personal communication to trick users into revealing sensitive information, such as log-in credentials, to an attacker. In this case, the user was deceived by a phone call that pretended to be from a legitimate source and asked for their log-in details.

Stratum 1 devices are the most accurate ntp time sources accessible via a network connection. A Stratum 1 device would normally be synchronised via a Stratum 0 reference clock.

The alert that the network engineer should configure based on the operation specifications is SNMP traps to report when the chassis temperature exceeds 95°F (35°C). SNMP (Simple Network Management Protocol) is a protocol that allows network devices to communicate their status and performance information to a central management system, called an SNMP manager. SNMP traps are messages that are sent by network devices to notify the SNMP manager of an event or condition that requires attention, such as an error, a failure, or a threshold violation. In this case, the network engineer should configure SNMP traps on the network devices to send an alert when their chassis temperature exceeds 95°F (35°C), which is the maximum operating temperature specified in the table. This alert would help the network engineer monitor and troubleshoot any overheating issues that could affect the network performance or availability. Reference: CompTIA Network+ N10-008 Certification Study Guide, page 228; The Official CompTIA Network+ Student Guide (Exam N10-008), page 8-11.

IGMP snooping is a feature that allows switches to monitor the IGMP (Internet Group Management Protocol) messages between hosts and multicast routers, and to learn which ports are interested in receiving which multicast groups.
IGMP snooping can improve the network performance by reducing the unnecessary flooding of multicast traffic to all ports, and by forwarding it only to the ports that have requested it.
IGMP snooping can also conserve bandwidth and CPU resources on the network devices and hosts, as they do not have to process unwanted multicast packets.
IGMP snooping can be especially useful for streaming video applications, as they often use multicast to deliver the same content to multiple devices simultaneously.
The other options are not relevant to addressing the issue of network performance degradation due to streaming video:
Implementing another DHCP server would not help, as DHCP is used to assign IP addresses and other network parameters to hosts, but it does not affect the multicast traffic or the streaming video quality.
Reconfiguring port tagging for the video traffic would not help, as port tagging is used to identify the VLAN membership of frames, but it does not control the multicast traffic or the streaming video quality.
Changing the SSID of the APs would not help, as SSID is used to identify the wireless network name, but it does not affect the multicast traffic or the streaming video quality. Reference:
CompTIA Network+ N10-008 Study Guide, Chapter 3: Network Protocols and Services, Section 3.2: Configure and Support IPv4 and IPv6, p. 179-180 Professor Messer's Network+ N10-008 Course Notes, Section 3.2: IPv4 and IPv6 Multicast, p. 37 Professor Messer's Network+ N10-008 Video Training Course, 3.2 IPv4 and IPv6 Multicast