单项选择题 A user receives an email slating that their account was compromised and there is a need to verify account credentials by submitting the correct information on a website. Which of the following security threats is occurring?（）

单项选择题 Which of the following protocols should be used to monitor network performance?（）

单项选择题 An administrator is setting up a security camera that will send the same feed to twelve of the twenty workstations on the network. Which of the following addressing schemes was designed for this scenario?（）