The correct answer is A. A hyperlink to the parent Account of the parent Opportunity.
A formula field can use cross-object references to parent records, and Salesforce states that cross-object formulas can reference fields from objects up to 10 relationships away. Since Opportunity Product relates to Opportunity, and Opportunity relates to Account, a formula on Opportunity Product can reference the parent Opportunity’s Account.
Salesforce also supports the HYPERLINK() formula function, which creates a clickable link from specified link text to a specified URL. So a formula field can be configured to create a hyperlink to the Account record related to the parent Opportunity.
B is incorrect because formula field data types do not include Rich Text Area as a formula return type.
C is incorrect because Salesforce restricts formulas from using long text area, encrypted, or Description fields.
D is not the best verified answer because large cross-object concatenations can run into formula relationship, size, or complexity limits, while the clearly supported Platform App Builder use case here is the cross-object HYPERLINK formula.
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