For a formula to evaluate to true when the stage is set to "Negotiation/Review" and the close date is less than one week away, the correct formula is:
* Option B. This formula uses the ISPICKVAL function to check the text value of a picklist and compares the CloseDate to a week from today:
AND( I AND(
ISPICKVAL(StageName, "Negotiation/Review"),
CloseDate - 7 < TODAY()
)SPICKVAL(StageName, "Negotiation/Review"), CloseDate - 7 < TODAY() )
This formula checks that both conditions are met: it confirms the stage name is "Negotiation/Review" and that the CloseDate is within the next 7 days from the current date.
Option A lacks the ISPICKVAL function necessary for evaluating picklist fields. Option C uses DAY(7) which is not a valid Salesforce formula expression. Option D also uses DAY(7) incorrectly and fails to use the ISPICKVAL function.
Reference for creating formula fields in Salesforce:
* Formula Field Reference:
https://help.salesforce.com/articleView?id=sf.customize_functions.htm&type=5

Removing the Delete permission from the Shipper profile and using a permission set to remove the Delete permission are both valid ways to prevent users from deleting delivery records. Removing the delete button from the Delivery page layout will not prevent users from deleting records using other methods, such as list views or reports. Changing the organization-wide default of deliveries to Private will not affect the delete permission, but only the sharing settings.

Explanation
A summary report on the opportunity object should be created to add to the account page layout. A summary report groups rows of data by common values and allows users to create charts based on aggregate values. A summary report on the opportunity object can group opportunities by stage and display a chart of all related opportunities on the account detail page.