What is the purpose of a reasonableness check on data submitted through a web form?

• A. Authentication
• B. Input Validation
• C. Data Encryption
• D. Session Management

Answer: (B)

Reasonableness checks are a form of input validation that ensures submitted data is plausible and consistent with the application's rules. They go beyond just correct formatting to verify that values make sense in context—for example, dates that aren’t in the future, numbers within expected ranges, or related fields that align logically (start date before end date). By catching obvious or illogical inputs at submission, you prevent bad data from entering the system and reduce downstream processing errors.

This differs from authentication (proving who the user is), data encryption (protecting data confidentiality), and session management (maintaining user state).