Explanation
To access a junction object record, a user needs to have at least read permission on one of its master records and on the junction object itself. If the user does not have access to either master record, they cannot access the junction object record. If the user has access to both master records, they can access the junction object record with the most permissive access level of either master record. References:
https://help.salesforce.com/s/articleView?id=sf.security_sharing_rules_types.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.relationships_manytomany.htm&type=5

Explanation
Email logs are files that provide information about email delivery and activity in your Salesforce org. Email logs contain details such as sender, recipient, subject, date, status, error code, and more for each email sent or received within a specified time range. You can use email logs to investigate issues with email delivery or performance in your org. In this case, you can use email logs to check if the status update emails were sent successfully or if there were any errors or failures. References:
https://help.salesforce.com/s/articleView?id=sf.email_logs.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.email_logs_format.htm&type=5

Explanation
Upsert is an operation that can either update existing records or insert new records based on the External Id field. This way, the administrator can match existing leads and add new ones with Data Loader. References:
https://help.salesforce.com/s/articleView?id=sf.data_loader_upsert.htm&type=5

Explanation
Two options that the administrator should check to ensure the product is available are:
Confirm the correct price book is selected on the opportunity. A price book is a list of products and their prices that can be added to an opportunity. An opportunity can have only one price book at a time, and the products that are available for selection depend on the price book that is chosen. Therefore, the administrator should check if the opportunity has the right price book that contains the new keyboard product.
Ensure the product is associated with the correct price book. A product is a good or service that can be sold in Salesforce. A product can be associated with one or more price books, depending on how it is priced for different markets or segments. Therefore, the administrator should check if the new keyboard product is added to the appropriate price book that is used by the opportunity.
The other two options are incorrect because:
Making custom fields does not affect the availability of products on an opportunity. Custom fields are used to store additional information or calculations on an object, but they do not determine which products can be selected from a price book.
Turning on field tracking does not affect the availability of products on an opportunity. Field tracking is used to monitor changes to certain fields on an object and display them in a history related list, but it does not determine which products can be selected from a price book.
References: https://help.salesforce.com/s/articleView?id=sf.products_pricebooks.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.products_define.htm&type=5

Explanation
A validation rule can enforce data quality by preventing users from saving records that do not meet certain criteria. In this case, the validation rule can check if both the Sales Engineer and the Account Executive lookup fields are blank, and display an error message if so. This way, the director of sales can ensure that every opportunity has either a sales engineer or an account executive assigned to the deal. References:
https://help.salesforce.com/s/articleView?id=sf.validation_rules_overview.htm&type=5