Correct answer: A-IV, B-III, C-I, D-II
The correct matches identify the relationships between the sugars: A (α-Glucose and α-Galactose) are epimers because they differ in configuration at one specific carbon; B (α-Glucose and β-Glucose) are anomers as they differ in configuration at the anomeric carbon; C (α-Glucose and α-Fructose) are functional isomers since they have the same molecular formula but different structures; D (α-Glucose and α-Ribose) are homologous as they are related by a common structural feature but differ in length.