An algorithm should output "OK" if a list's numbers are all non-zero, else the output is "Not OK." Which test is a valid test of the algorithm?

The rationale behind choosing the test involving the input 99, 0, 5 is that it accurately assesses the algorithm's ability to identify the presence of zero in the list of numbers. The stipulation of the algorithm is to output "OK" only if all numbers are non-zero. Since the list includes a zero, the proper output should be "Not OK."

This test effectively checks the algorithm's functionality by evaluating a scenario where at least one number is zero, which directly contradicts the requirement for a successful "OK" output. It ensures that the algorithm correctly classifies lists with zeros as not meeting the non-zero criteria and provides the expected outcome of "Not OK."

With regard to the other choices, they either do not meet the conditions specified by the algorithm or yield the wrong expected outcome based on the rules set forth. In this context, the chosen input is a clear and valid test case that validates the algorithm's logic.