Final answer:
A higher specificity constant of an enzyme indicates higher efficiency due to a combination of a fast catalytic rate and a high substrate affinity.
Step-by-step explanation:
A higher specificity constant (kcat/KM) of an enzyme indicates a higher efficiency of the enzyme. Efficiency in enzymatic terms refers to how well an enzyme converts substrate into product. This specificity constant is a measure that combines two factors: the rate of the catalytic process (kcat) and the enzyme's affinity for its substrate (KM). A higher kcat/KM means the enzyme catalyzes the reaction quickly (high kcat) and has a high affinity for the substrate (low KM), therefore, the correct answer is option a) Higher efficiency.