Which specimen requires chilling during transport to the laboratory?

Chilling during transport is crucial for certain specimens to ensure their stability and prevent degradation. Lactic acid specimens specifically require chilling because elevated temperatures can lead to an increase in lactic acid levels due to cellular metabolism. If the sample is not properly chilled, the results may be falsely elevated, compromising the accuracy of the test.

In contrast, while glucose samples also require careful handling, they do not necessarily need to be chilled during transport. Serum for chemistry analysis usually has its own set of requirements but does not typically necessitate chilling. Complete blood counts are best processed promptly at room temperature and do not require chilling to maintain their integrity. Therefore, the requirement for cooling during transport makes lactic acid specimens the correct answer in this scenario.