To determine which of these options is a valid Boundary Value Analysis (BVA) test case, we need to understand the tax brackets and how they apply to the salary.
According to the given information:
- The first $4000 of salary is tax-free.
- The next $1500 is taxed at 10%.
- The next $28000 is taxed at 22%.
- Any further amount is taxed at 40%.
Now, let's go through each option to see if it falls within a boundary value or not:
Option A) $1500 - This amount falls within the first tax bracket of $1500, which is taxed at 10%.
Option B) $32001 - This amount exceeds the highest taxable bracket of $28000. Therefore, it falls within the boundary of the highest tax bracket and would be taxed at 40%.
Option C) $28000 - This amount falls within the second tax bracket of $28000, which is taxed at 22%.
Option D) $33501 - This amount exceeds the highest taxable bracket of $28000. Therefore, it falls within the boundary of the highest tax bracket and would be taxed at 40%.
Based on the given information, the valid BVA test case is:
D) $33501
This is because it falls within the boundary of the highest tax bracket and would be taxed at 40%.
Therefore, the correct answer is D) $33501.