Final answer:
The products of the given reaction, where a racemic mixture reacts with an enantiomerically pure reagent, are best described as a pair of diastereomers since they can be separated based on their differing properties.
Step-by-step explanation:
The question you're asking relates to a reaction product's stereochemical outcome. Based on the information provided, if a racemic mixture is treated with an enantiomerically pure reagent, the process is known as diastereomeric resolution. The products formed in this process are diastereomers, which have different physical and chemical properties and can be separated. Once separated, reversing the reaction will yield the original enantiomers. Therefore, given a reaction between a racemic mixture and a single enantiomer of a different compound, the product(s) can best be described as a pair of diastereomers (c). It's important to note that enantiomers are mirror images that cannot be superimposed on each other, and a molecule must have at least four different atoms or groups connected to a chiral center to exhibit enantiomerism.