Explanation:
Copper is necessarily associated as an activator in the enzyme tyrosinase.

Tyrosinase:
- Tyrosinase is an enzyme that is involved in the production of melanin, which is responsible for the pigmentation of skin, hair, and eyes.
- It catalyzes the conversion of the amino acid tyrosine to DOPA (dihydroxyphenylalanine) and then to dopaquinone, which is a precursor for melanin synthesis.
- The enzyme contains two copper ions in its active site, which are essential for its catalytic activity.

Role of Copper in Tyrosinase:
- Copper is required for the proper folding and stability of tyrosinase.
- It serves as a cofactor, meaning it is necessary for the enzyme to function properly.
- Copper ions in the active site of tyrosinase help in the coordination and binding of the substrate (tyrosine) and facilitate its conversion to dopaquinone.
- The active site of tyrosinase consists of three histidine residues that coordinate with the copper ions, forming a copper center that is crucial for the enzymatic activity.

Other Enzymes:
- Carbonic anhydrase: Copper is not necessarily associated as an activator in carbonic anhydrase. Carbonic anhydrase contains a zinc ion in its active site, which is essential for its catalytic activity.
- Tryptophanase: Copper is not necessarily associated as an activator in tryptophanase. Tryptophanase is a pyridoxal phosphate (PLP)-dependent enzyme, meaning it requires the cofactor PLP (a form of vitamin B6) for its catalytic activity.
- Lactic dehydrogenase: Copper is not necessarily associated as an activator in lactic dehydrogenase. Lactic dehydrogenase is a zinc-dependent enzyme, meaning it requires zinc as a cofactor for its catalytic activity.

Therefore, the correct answer is option D) Tyrosinase, as copper is necessarily associated as an activator in this enzyme.