Which of the following is a boundary value test for a user interface form?

• A. Submitting an incomplete form
• B. Testing entered values that are out of bounds
• C. Canceling an action
• D. Submitting a complete form

Answer: (B)

Boundary value testing targets the edges of input domains. In a UI form, this means checking values right at the limits of what the field should accept and just outside those limits to verify the system rejects them or handles them properly. This focus makes it the best fit because it directly exercises how the form validates input at the boundaries, catching off-by-one errors or improper validation. Submitting an incomplete form tests required-field validation and flow, not the edge values. Submitting a complete form tests the normal path. Canceling an action checks UI workflow rather than boundary validation. For a field that accepts 1–100, boundary testing would involve values like 1 and 100 (within bounds) and 0 or 101 (outside) to confirm correct handling.