<p>We can read this question sentence as:</p><p><strong>Since many of the exhibition's visitors were surprised by the high ticket prices, many of the exhibition's visitors were reluctant to enter the place and chose to go somewhere else.</strong></p><p><p>This sentence is a complex sentence with a main clause and an adverbial clause. The adverbial clause is "<span>Since many of the exhibition's visitors were surprised by the high ticket prices</span>". The main clause is "<span>many of the exhibition's visitors were reluctant to enter the place and chose to go somewhere else</span>."</p><p><strong>Reducing the adverbial clause to the adverbial phrase.</strong></p><p>An adverb clause can be reduced to an adverbial phrase by removing the subject and the be-verb when they are not essential to the meaning of the sentence.</p></p><div><p>Here's a step-by-step breakdown:</p><ol><li><p><strong>Identify the Subject and Verb in the Adverb Clause</strong>: The subject is "many of the exhibition's visitors" and the verb is "were surprised."</p></li><li><p><strong>Identify Redundancy</strong>: In the main clause, "many of the exhibition's visitors" is also the subject. So, when reducing the adverb clause, the subject "many of the exhibition's visitors" in the adverb clause is redundant and can be omitted.</p></li><li><p><strong>Change the Verb</strong>: The verb "were surprised" is an passive voice, so it should be transformed into its past participle form "surprised" to create an adverbial phrase.</p></li><li><p><strong>Omit the Subordinating Conjunction</strong>: The subordinating conjunction "Since" is also often omitted when the adverb clause is reduced to a modifying phrase.</p></li></ol><p>Resulting Adverbial Phrase: "Surprised by the high ticket prices,".</p><p>The correct answer is (D) Surprised.</p></div>