The correct choice is the one that will still work after release. The best answer is B. Street & BR () & Planet Galaxy_) City_c & " , " & Planet_ca & Galaxy_0. The decision turns on formula logic. Formula and validation expressions must respect Salesforce data types. Picklists require picklist-aware handling, dates require date functions or date arithmetic, and image or text formulas must return the correct type.
This is how the same requirement would be handled in a well-governed Salesforce org: identify the controlling object, relationship, field, page, automation, or environment first, and then configure the native capability for that control point. The selected answer satisfies the requirement without requiring users to perform extra interpretation or administrators to maintain an unnecessary custom workaround.
The distractors are not equal substitutes. A (Street r (City & " ,) handles a different concern; it handles only part of the requirement and leaves the controlling Salesforce behavior unresolved. C (Street & (City & " , " & Planet & " & Galaxy_0}) should be rejected because it works at the wrong scope for the object, field, page, automation, or deployment condition in the stem. D (Street r & BR () & City & " , " & Planet _ * & & Galaxy_r) would be fragile here because it could produce an inconsistent result once different users, records, or apps are tested. That is the kind of solution a Salesforce admin can document, migrate, and troubleshoot without creating hidden technical debt.
---