<u><em>Shelby visited the zoo’s new panda exhibit.</em></u>
Explanation:
A sentence written in the <u>active voice</u> is the one that places attention on what the<u> subject</u> does. As in the example provided, the subject, <em>Shelby</em>, does the action and is before the verb.
On the other hand, a sentence written in the <u>passive voice</u> is the one that focuses on the action, and not on the subject, for example: <em>The zoo's new panda exhibit was visited by Shelby. </em>