What issue could lead to a rejection of water samples for testing?

Rejection of water samples for testing can occur due to multiple factors that compromise the integrity and reliability of the test results. Insufficient labeling is critical because without proper identification, it becomes nearly impossible to trace the samples back to their collection points or determine the conditions under which they were taken. This could lead to confusion and misinterpretation of results.

Delayed transport is another significant issue, as the timing between sample collection and delivery can affect the viability of certain parameters being tested. Organisms, chemical properties, or other characteristics might change during prolonged transport, rendering the sample unsuitable.

Improper storage conditions can also lead to sample degradation. If samples are not stored at the correct temperature or in the right environment, this could alter their chemical or biological composition, thus skewing test outcomes.

When considering all these factors together, it becomes clear that each individual issue can independently cause a sample to be rejected. Therefore, the selection indicating that all of these issues could lead to rejection accurately reflects the comprehensive nature of proper sample handling protocols.