Cadmium and zinc coatings provide which of the following types of protection for the base metal?

Correct Answer: Option D — Sacrificial.

Cadmium and zinc coatings act as sacrificial anodes when applied to steel components. Because these metals are more anodic than the base metal, they corrode preferentially in the presence of moisture and salt, effectively protecting the underlying structure from oxidation and galvanic corrosion in harsh marine environments.