Explanation
According to the Salesforce documentation, the place on a prospect record where the user would look to see if a prospect had registered for a webinar is: C) Prospect Activities. A prospect record is a feature that shows the detailed information and activity history of a prospect in Marketing Cloud Account Engagement. A prospect record can be accessed from the Prospects tab in Marketing Cloud Account Engagement, and it can show different sections of information for the prospect, such as details, insights, activities, or custom fields. The Prospect Activities section shows the chronological list of actions and events that the prospect has performed or received, such as opening an email, clicking a link, submitting a form, or registering for a webinar. The user can use the Prospect Activities section to see if a prospect had registered for a webinar, and to see other details of the webinar registration, such as the date, time, or status. The user can also filter, search, or export the Prospect Activities section. The Contents, Insights, or Custom Fields sections are not the places on a prospect record where the user would look to see if a prospect had registered for a webinar, as they are related to other aspects of the prospect information, such as content preferences, engagement metrics, or custom data.
References: Salesforce documentation

Explanation
According to the Salesforce documentation, the answer is true. You can see the score, grade, assigned user and recent interaction within the Insight section of the Prospect Record. The Insight section is a feature that shows the key information and metrics of a prospect in Marketing Cloud Account Engagement. The Insight section can be accessed from the Prospects tab in Marketing Cloud Account Engagement, and it can show different data for the prospect, such as score, grade, assigned user, or recent interaction. The score is a numerical value that indicates the level of interest and engagement of a prospect, based on their activities, such as opening an email, clicking a link, or submitting a form. The grade is a letter value that indicates the level of fit of a prospect, based on their attributes, such as industry, job title, location, or company size. The assigned user is the user who is responsible for the prospect, and who can view and edit the prospect's information. The recent interaction is the latest action or event that the prospect has performed or received, such as opening an email, clicking a link, or registering for a webinar. The Insight section can help users to quickly and easily view the most important information and metrics of a prospect, and to take actions based on the data.
References: Salesforce documentation

According to the Salesforce documentation, if Salesforce has a custom field of the same name on Leads and Contacts, Marketing Cloud Account Engagement pulls the field name from the Lead field. A custom field is a field that is created by the user to store additional information that is not available in the standard fields. A custom field can be created and managed by the administrator in the Admin tab in Marketing Cloud Account Engagement or Salesforce, and it can be synced between the two platforms. A custom field can have the same name on different objects, such as Leads and Contacts, but it can have different values or settings. If Salesforce has a custom field of the same name on Leads and Contacts, Marketing Cloud Account Engagement pulls the field name from the Lead field, as it is the primary source of the field name. Marketing Cloud Account Engagement does not pull the field name from the Contact field, as it is the secondary source of the field name. However, Marketing Cloud Account Engagement can pull the field value from either the Lead or the Contact field, depending on which object the prospect is associated with in Salesforce. For example, if Salesforce has a custom field called "Industry" on both Leads and Contacts, Marketing Cloud Account Engagement will pull the field name "Industry" from the Lead field, but it will pull the field value from either the Lead or the Contact field, depending on the prospect's record type in Salesforce. Reference: Salesforce documentation

Explanation
A CNAME or vanity alias is used to provide a seamless transition for your prospects when visiting pages and forms that you host on your site and Marketing Cloud Account Engagement hosted campaign elements such as landing pages, search results and individually tracked links sent in your emails. This is true because a CNAME allows you to use your own domain name instead of the default go.Marketing Cloud Account Engagement.com domain name, which enhances your branding and trustworthiness.