The participle phrase in the sentence is B. Clapping wildly.
<em>Participle phrases</em> are phrases that contain a <em>present or past participle</em> and that function as adjectives. In this case, the phrase <em>Clapping wildly </em>is describing the subject of the sentence, which is the audience. Thus, the participle phrase is giving more information about the subject as if it was an adjective.
