The correct answer is A. Web-to-Case is the Salesforce feature designed to let visitors submit case information from a public-facing website. Salesforce documentation states that Web-to-Case is set up by enabling the feature, creating and customizing a web form, and adding that form to a website.
Why others are incorrect:
B). Outbound message sends data out of Salesforce; it does not create cases from a website.
C). Screen flow could require extra site/guest-user setup and is not the standard feature for this requirement.
D). Email-to-case creates cases from inbound email, not directly from a public web form.

A Template-Triggered Prompt Flow is specifically designed to provide dynamically retrieved Salesforce data and additional logic to Prompt Builder templates. Salesforce states that these flows perform logic and actions that generate output text merged into the associated prompt template. The app builder can retrieve the Contact
' s related Order records, construct appropriate prompt instructions, and pass that grounded context back to the Field Generation prompt template. Salesforce also documents the Add Prompt Instructions element as available specifically in template-triggered prompt flows. A record-triggered flow responds to database changes, while a schedule-triggered flow runs at predefined intervals. A generic autolaunched flow does not provide the dedicated Prompt Builder integration required by the scenario. Therefore, A is the correct flow type for grounding this prompt template.

The correct answer is B. Edit a record page using Lightning App Builder > Drag the component onto the page.
A custom Lightning component installed from AppExchange is configured on a Lightning record page through Lightning App Builder. Salesforce documentation states that Lightning App Builder supports custom Lightning components, including Aura and Lightning web components, and record pages are edited as Lightning pages.
The Page Layout editor is used for fields, buttons, related lists, and layout behavior, not for placing Lightning components on a Lightning record page. App Manager manages apps and utility bars, but the page canvas configuration is done in Lightning App Builder.

The correct answer is A. Allow Salesforce to import Contacts from mobile device Contact lists.
Salesforce supports importing contacts from a mobile device contact list into Salesforce from the Salesforce mobile app using Import from Device. Salesforce also notes that users need the permission Allow Salesforce to import Contacts from mobile device Contact lists to use this feature.
Why others are incorrect:
B only notifies users; it does not move phone contacts into Salesforce.
C helps users create/edit records offline in Salesforce, but it does not import contacts already entered in the phone's contact list.
D is for account-contact relationship modeling, not mobile contact capture.

The correct answers are C. Unique and D. External ID.
The legacy ID should be stored in a custom field marked as an External ID because Salesforce uses External ID fields to identify records from an outside system and to support update/upsert operations during future data loads. The field should also be marked Unique so each legacy system ID maps to only one Salesforce Account record and avoids duplicate-match problems during upsert. Salesforce documentation defines External ID fields as fields that contain record identifiers from outside Salesforce and can be used to update or upsert records.
A). Required is not necessary for the upsert-matching requirement.
B). Encrypted/Text encrypted is not appropriate because encrypted fields are not used for this legacy-ID matching purpose.