Final answer:
Without the molecule's structure provided in the question, it is not possible to determine the absolute configuration of its chiral centers. However, the descriptors R and S are used to specify the configuration based on the arrangement of the substituents around each chiral center as per Cahn-Ingold-Prelog priority rules.
Step-by-step explanation:
The absolute configuration of a molecule's chiral centers is described by the R or S descriptors, based on the spatial arrangement of the substituents around each chiral center. When a molecule has multiple chiral centers, each one is assigned an R or S descriptor, which is then combined with the locant number indicating the position of the chiral center within the molecule. Unfortunately, as the molecule's structure is not provided in your query, I am unable to determine the absolute configuration for those chiral centers. However, options B. 1S, 2S and C. 1S, 2R for example, would indicate that for the first chiral center, if you prioritize the substituents according to the Cahn-Ingold-Prelog priority rules, the arrangement is counterclockwise or 'S', and for the second chiral center, it could either be 'S' or 'R' depending on the spatial arrangement of its substituents.