A presumptive test is best described as which of the following?

• A. Waived test
• B. Nonwaived test
• C. Definitive test
• D. Presumptive test

Answer: (D)

Screening tests provide rapid, inexpensive indication that a substance might be present, but they are not definitive. Presumptive tests are typically simple and yield a preliminary result (often a color change or similar signal) that suggests possible presence, guiding further testing. Because they aren’t specific enough to identify the exact compound or determine precise quantity, a definitive confirmatory test (such as GC-MS or LC-MS/MS) is needed to make a final determination. The terms waived or nonwaived describe regulatory categories, not the inherent nature of a presumptive test, so the best description is that it is a presumptive (screening) test.