Answer:
d. the position of the labeled carbon can be traced through products of the pathway to characterize the pathway reactions.
Step-by-step explanation:
Isotopic labeling is a type of technique that has an important role in the identification or detection of the pathway during the reaction or in the cell. In this technique, the reactant is labeled and the labelled reactant is used in the reaction. When C13 is used to identify the pathway, the labeled carbon is easily identified in the products and thus the pathway of the reaction can be detected.