Answer:
The correct answer is option C. Polio is a contagious *disease* that has mostly been eradicated.
Step-by-step explanation:
A predicate nominative, also known as predicate noun, is always a noun or pronoun that renames the subject and complete a linking verb.
Bearing the above in mind, it could be said that from the options provided, the option C. Polio is a contagious *disease* that has mostly been eradicated is the one that includes a predicate nominative (disease in this case).