Which statement describes a nonspecific preliminary drug test?

• A. To measure precise quantities of a substance.
• B. To indicate possible substances using nonspecific, preliminary tests.
• C. To identify substances by full molecular structure.
• D. To quantify purity of a sample.

Answer: (B)

Nonspecific preliminary drug tests are screening tools designed to quickly flag whether a sample might contain drugs, without identifying the exact substance. They’re qualitative and rapid, giving a potential “yes, there could be a drug here,” which then leads to confirmatory testing to determine the specific compound.

That’s why the statement describing indicating possible substances using nonspecific, preliminary tests is the best choice. It captures the idea of a quick, non-targeted check to suggest what might be present, rather than providing precise quantities, identifying full molecular structures, or assessing purity.

The other options describe activities that come later or are more exact: measuring precise quantities is quantitative and not preliminary; identifying substances by full molecular structure is a definitive, confirmatory goal; quantifying purity is also a separate, quantitative assessment.