Universal Containers is implementing a community of High-Volume Community users. Community users should be able to see records associated to their Account or Contact record. The Architect is planning to use a Sharing Set to provide access to the records. When setting up the Sharing Set, certain objects are not available in the list of Available Objects. Which two reasons explain why an object is excluded from the list of Available Objects in a Sharing Set?

Universal Container has developed a custom Visualforce page that will accept user input and must prefer returning the results to the users.
Which two techniques should be used to ensure the users cannot perform a SOQL injection attack?

Universal Containers' organization wide-defaults model is private for the Account object. A sales repeats to opportunity records.
Which level of access will the sales rep have to the related account record?

Universal Containers (UC) implemented Sales Cloud and requested that sales agents have access to products the company sells and be able to create opportunities for its customers.
What should the Organization-Wide Defaults (OWD) be for pricebook?

To grant Universal Containers sales manager access to shipment records properly, it was necessary to leverage Apex managed sharing. The IT team is worried about improper access to records.
Which two features and best practices should a Salesforce architect recommend to mitigate this risk?