Explanation
The prospect's Audits tab shows the history of changes made to the prospect's record, such as field updates, list changes, and assignment dates. These data points can help determine what updates were made during the database clean-up project and how they affected the prospects. The Lifecycle Report, the amount of time the prospect spent viewing the website, and the unique clicks are not data points that can be found in the Audits tab, but they can be found in other reports or tabs in Marketing Cloud Account Engagement. References Prospect Audits

Explanation
The recommended way to accomplish sending out a new whitepaper to prospects and tracking who opens the PDF is to upload the whitepaper PDF as a content file and link to it in the body of the email. A content file is a type of file that can be uploaded and stored in the Content Builder, which is a tool that allows marketers to create and manage content assets. A content file can be linked to in the body of an email, which allows prospects to access the file by clicking the link. By linking to a content file, marketers can also track who opens the PDF, as the link will generate a tracking code that records the open activity. Uploading the whitepaper PDF as a content block, attaching it to the email, or embedding it in the email are not recommended ways to accomplish sending out a new whitepaper to prospects and tracking who opens the PDF, as they either do not allow linking, do not allow tracking, or do not display properly. References: :
Content Files

The number that would display on the Report Card for the email send statistic is 100. This is because the Report Card shows the total number of prospects that have reached a specific step in the program, regardless of the date range that you filter by. The date range filter only affects the data that is shown in the Engagement History table, which shows the number of prospects that have taken a specific action on a specific date. Therefore, even if the user filters the program to show a date range of Tuesday through Friday of last week, the Report Card will still show that 100 emails were sent on Monday, as that is the total number of prospects that reached the first step of the program

A prospect is a visitor who has submitted an email address through a form or landing page on your site. This is the primary way that Marketing Cloud Account Engagement identifies and converts visitors into prospects. A prospect can also be created from an email link click, a manually entered email address, or an import.

Explanation
When an engagement studio program is created with an Email Send action step immediately followed by an Email Open trigger step with a 3 day wait, it means that the program will wait for up to 3 days for the prospect to open the email. If the prospect opens the email within the 3 day period, they will immediately progress down the "Yes" path (A). The prospect will not wait for any additional time after opening the email (B), nor will they progress down the "No" path (C, D). References: Engagement Studio Overview