Question

which describes the underlined word in the sentence? sam's medieval chess set is unique. underlined words: unique a. indirect object b. direct object c. predicate adjective d. predicate nominative

Answer 1

The underlined word unique is used as C. predicate adjective in the sentence.
A predicate adjective is the adjective following a copulating/linking verb.
The linking verb here is is, and the predicate adjective is therefore the adjective following it, which is unique. 

Answer 2

the answer is most definate c