TOEIC Reading 5 Exercisee 20

<p dir="ltr"><span><span>The question is a complex sentence. The main clause “Natural gas is used for producing fertilizer” is embedded with an adjective clause that simply gives additional information about the antecedent “natural gas.”</span></span></p><p dir="ltr"><span><span>Let’s focus on the adjective clause “, _______ price is equivalent to that of oil,.” Since the blank directly follows a noun, it should be filled with a possessive relative pronoun. So, the correct answer is Choice (D) "</span><span>whose"</span><span>.&nbsp;</span></span></p><p dir="ltr"><span><span>(A) "</span><span>which"</span><span> can be a relative pronoun used as the subject or object in an adjective clause and modifying an antecedent that refers to something.&nbsp;</span></span></p><p dir="ltr"><span><span>(B) "</span><span>what"</span><span> can be a compound relative pronoun that means “anything that,” the combination of a noun and a relative pronoun.&nbsp;&nbsp;</span></span></p><p dir="ltr"><span><span>(C)</span><span>&nbsp;"that"</span><span> can be a relative pronoun used as the subject or object in an adjective clause and modifying an antecedent that refers to either someone or something. None of them can be possessive relative pronouns, so they are incorrect.</span></span><br></p>