A Platform App Builder is working with a client to format shipping ZIP codes.

A validation rule is the correct mechanism because the requirement is to prevent invalid ZIP-code formats from being saved. Salesforce supports the REGEX() function in validation rules specifically for enforcing structured input patterns. Salesforce ' s own validation examples include a five-digit American ZIP-code pattern using regular expressions, demonstrating this exact use case. The rule can evaluate the shipping postal-code field and return TRUE whenever the value does not consist of exactly five digits, causing Salesforce to block the save and display an error. Help text only advises users and cannot enforce the format. A Screen Flow would affect only records entered through that particular interface, while an approval process is excessive and does not provide immediate data-format validation. Therefore, B provides consistent enforcement at the record-validation layer.

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