A testable acceptance criterion is a condition that can be verified or measured objectively by the tester, customer, or stakeholder. It should be specific, measurable, achievable, relevant, and time-bound (SMART). A testable acceptance criterion should also be written from the user’s perspective, achievable within the sprint, and written before development begins1.
Among the four options, only option C meets these criteria. It is specific (the response time to confirm a customer submission), measurable (must not exceed 5 seconds), achievable (within the technical and business constraints), relevant (to the user’s needs and expectations), and time-bound (must be met in every sprint). It is also written from the user’s perspective, testable (by measuring the response time), and written before development (as part of the user story definition).
Option A is not testable because it is vague and subjective. What does it mean to support business processes? How can this be verified or measured? Option B is also not testable because it is subjective and ambiguous. What does it mean to be easy to use? How can this be verified or measured? Option D is not testable because it is not written from the user’s perspective. It is an internal quality criterion for the testing team, not an acceptance criterion for the product or feature.
[References: ISTQB Foundation Level Agile Tester Syllabus, Section 2.3.2, page 182; ISTQB Foundation Level Agile Tester Sample Exam Questions, Question 2.3.2-2, page 93, ]