Assuming the underlined word is 'old-fashioned,' the correct answer is D. predicate adjective.
Predicate adjective is the first adjective after a linking verb which connects two parts of a sentence. Here, the linking verb is 'seems' and the first adjective following it is 'old-fashioned,' which makes it a predicate adjective, rather than predicate nominative which would be a noun, not an adjective.