Read the sentence. alma plans to visit london and paris, where her parents went on their first trip together as a married couple. what best describes the underlined part of the sentence, and why? a. it is a restrictive relative clause because it begins with a relative pronoun, has both a subject and a verb, and is not necessary to the meaning of the sentence. b. it is a nonrestrictive relative clause because it begins with a relative pronoun, has both a subject and a verb, and is necessary to the meaning of the sentence. c. it is a restrictive relative clause because it begins with a relative pronoun, has both a subject and a verb, and is necessary to the meaning of the sentence. d. it is a nonrestrictive relative clause because it begins with a relative pronoun, has both a subject and a verb, and is not necessary to the meaning of the sentence.