Final answer:
To identify the process transforming Compound 2 into Compound 3, the addition of hydrogen to the molecule signals a reduction reaction, making reduction the correct answer.
Step-by-step explanation:
The question refers to the chemical transformation of Compound 2 into Compound 3. To determine if Compound 3 is the result of an oxidation, reduction, hydrolysis, or carboxylation reaction, we need to look at what changes are occurring at the molecular level.
Based on the information given, if hydrogen is being added to the original reactant molecule, this is indicative of a reduction reaction. Conversely, hydrogen being removed or oxygen being added would suggest an oxidation process. As no information suggests the breaking of a compound into smaller pieces with water (hydrolysis), or the addition of a carboxyl group (carboxylation), the correct answer is B. Reduction since the compound is most likely gaining hydrogen or electrons, which is a hallmark of reduction.