<p dir="ltr">This question sentence is a first conditional. The first conditional predicts what will happen in the future. </p><p>The first conditional:</p><div dir="ltr" align="left"><table class="classic-table"><colgroup><col></colgroup><tbody><tr><td><p dir="ltr">(1) If + S + simple present, S + will/ can/ shall/ may + the basic form of a verb</p><p dir="ltr">(2) If + S + simple present, an imperative sentence. </p></td></tr></tbody></table></div><p><br></p><p>Based on Pattern 2: If + S + simple present, an imperative sentence, the answer is (C) "cut down on". </p><p dir="ltr">In most cases, an English sentence should have at least one subject, but there are exceptions: imperative sentences. An imperative sentence directly starts with the basic form of a verb, with the implied subject “you” omitted. Thus, the main clause should be an imperative sentence, and the blank should be filled with the basic form of a verb. </p>