Explanation
Dynamic lists are lists that automatically add or remove prospects based on criteria that you define. Prospects can be "unmatched" from a dynamic list if they no longer meet the criteria. For example, if you have a dynamic list of prospects who have opened an email in the last 30 days, and a prospect does not open any email for 31 days, they will be removed from the list. Automation rules and segmentation rules do not
"unmatch" prospects, they only apply actions to prospects that match the criteria

Explanation
The aspect of a Prospect record that represents their overall level of interest is Score. The score is a numerical value that measures the implicit interest of a prospect based on their engagement with marketing activities, such as opening emails, clicking links, and visiting landing pages. The score can increase or decrease based on the actions that a prospect takes, and can help marketers prioritize and segment their prospects. Grade, Profile, and Account are not aspects of a Prospect record that represent their overall level of interest, as they measure different attributes of a prospect, such as their explicit fit, their completeness, or their company information3.
References: 3: Scoring and Grading Prospects

Explanation
A Marketing Cloud Account Engagement instance can have only one CRM connector verified at one time. A CRM connector is a feature that allows you to connect your Marketing Cloud Account Engagement account with your CRM system, such as Salesforce or Microsoft Dynamics. A CRM connector enables bi-directional data sync between Marketing Cloud Account Engagement and your CRM, and allows you to align your marketing and sales processes. You can only have one CRM connector verified at one time, because Marketing Cloud Account Engagement can only sync with one CRM system at a time. If you want to switch to a different CRM system, you need to disconnect your current CRM connector and verify a new one

Explanation
The Marketing Cloud Account Engagement function that should be used to track prospect engagement on a banner ad on a third-party site is custom redirect. A custom redirect is a feature that allows you to track and measure the click-through rate of any online marketing content, such as banner ads, social media posts, or email links. You can use custom redirects to create trackable URLs for your banner ads, and monitor how many prospects click on them. You can also use custom redirects to perform actions on the prospects who click on them, such as adding them to a list, assigning them to a user, or changing their field values

Explanation
By default, Marketing Cloud Account Engagement will sync with contact accounts in Salesforce. Contact accounts are the standard account type in Salesforce, where each account can have multiple contacts related to it. Marketing Cloud Account Engagement can sync with contact accounts and their related contacts, leads, and opportunities. However, Marketing Cloud Account Engagement can also sync with person accounts in Salesforce, if they are enabled in your org. Person accounts are a special account type in Salesforce, where each account is also a contact. Marketing Cloud Account Engagement can sync with person accounts and their related opportunities, but not with leads. To sync with person accounts, you need to enable the option in the Salesforce connector settings in Marketing Cloud Account Engagement. For more details -> 121314