In Order to Inexpensively Determine the Contamination Level of a Sample

Multiple Choice

In order to inexpensively determine the contamination level of a sample of water, a new test is known to yield almost exactly the same value when repeatedly used on samples from the same container of water. However, these individual values are not close to the true average contamination level for the large container. The concern with using this new, cheaper test to determine the contamination level for a single sample of water is that this measurement method is not:

A) unbiased.
B) random.
C) valid.
D) reliable.
E) variable.