In GuidewireValidation Rules, the rejectField method is a critical tool for identifying specific fields that fail business logic checks. This method allows the application to highlight the exact UI widget in red and provide a specific error message to the user.

As indicated by the compiler error, the rejectField method on a Guidewire entity (like Contact or Claim) has a very specific signature that requiresfive parameters:

Field Name (String):The name of the property being validated (e.g., "State").

Validation Level (ValidationLevel):The severity of the failure (e.g., TC_LOADSAVE).

Error Message (String):The text displayed to the user.

Error Group (ValidationLevel):An optional group for categorizing the error.

Error ID (String):An optional unique identifier for the specific error.

When the compiler reports"Expected 5, got 3", it means the developer only provided the first three arguments. To resolve this error according to Guidewire best practices, the developer must complete the signature. While null is often passed for the final two arguments if they are not needed, the compiler requires them to be present so it can identify which version of the overloaded rejectField method is being called.

The reason Option A is the recognized answer in this context is that simply adding null, null is often insufficient if the types aren't explicitly recognized or if the code had "placeholder" nulls that didn't match the expected typekey/string types. By ensuring the 4th argument is aValidationLeveltypekey and the 5th is aString, the developer satisfies the Gosu compiler's strict type-checking requirements. This ensures the validation logic is correctly registered within the current bundle transaction and will properly interrupt the commit process if the condition is met.