Boundary Value Analysis (BVA) is a test design technique that focuses on testing at the edges, or boundaries, of input domains. The application has two specified input domains: the number of items in a list (valid range: 0 to 50) and the number of saved lists (valid range: 0 to 3).

For the number of items [0, 50], the boundary values are 0 and 50. BVA requires testing the minimum (0), the value just above the minimum (1), the maximum (50), and the value just above the maximum (51).

For the number of lists [0, 3], the boundary values are 0 and 3. BVA requires testing the minimum (0), the value just above the minimum (1), the maximum (3), and the value just above the maximum (4).

Option B is the only choice that includes all these necessary test conditions for both domains, representing the minimum set for 100% BVA coverage.

A. This option provides only a single, non-boundary value and is therefore completely insufficient for BVA.

C. This option omits several critical boundary values (e.g., 1 and 50 items; 0, 1, and 4 lists) and incorrectly includes an equivalence partitioning value (25 items).

D. This option misses key boundary values (e.g., 50 and 51 items; 4 lists) and includes arbitrary values not derived from BVA.

1. ISTQB® Certified Tester Foundation Level Syllabus, Version 2018 v3.1.1. Section 4.2.2, "Boundary Value Analysis (BVA)", Page 41. This section explains that BVA is used to test the boundaries of partitions, including the minimum and maximum values and the values immediately adjacent to them. The example provided for a range of 1 to 10 includes tests for 0, 1, 2 and 9, 10, 11, which supports testing the boundary and its immediate neighbors.

2. Pezzè, M., & Young, M. (2008). Software Testing and Analysis: Process, Principles, and Techniques. Wiley. Chapter 11, "Domain Testing", Section 11.2.2 "Boundary Testing". This academic text, widely used in university curricula, describes boundary testing for a closed interval [min, max] as testing points on the boundary (min, max) and points just off the boundary (min-1, max+1). This directly supports the test values chosen in the correct answer.

3. Kaner, C., Falk, J., & Nguyen, H. Q. (1999). Testing Computer Software. Wiley. Chapter 8, "Boundary testing and equivalence classes". This foundational text details that for a range, testers should check the exact endpoints, values just above and below the endpoints, and typical values. The set in option B is a direct application of this principle.