<p><span style="font-size: 13.008px;">The correct answer is </span><strong style="font-size: 13.008px;">(A) reinforce</strong><span style="font-size: 13.008px;">.</span><br></p>
<p>The verb "reinforce" means to strengthen or make something stronger. In this context, the firm wants to strengthen or enhance their relationship with their VIP clients. By inviting them to the concerts they sponsor, the firm is reinforcing their bond with these clients.</p>
<p>The other options are not suitable in this context:</p>
<p>(B) "Expose" means to make something visible or known. It does not convey the idea of strengthening a relationship.</p>
<p>(C) "Practice" means to perform an activity or exercise regularly. It does not fit the context of the sentence, which is about maintaining a relationship with VIP clients.</p>
<p>(D) "Gather" means to come together or collect. It does not convey the idea of strengthening a relationship.</p>