To determine the context clues that best point to the definition of "boisterous" in the second sentence, you should look for words or phrases that suggest a lively, energetic, or noisy behavior, as "boisterous" typically refers to someone or something that is noisy, energetic, or cheerful.
Among the provided options, "whooping; cheering" contains words that imply a lively and noisy atmosphere, which aligns with the definition of "boisterous."
Thus, the best set of context clues is:
whooping; cheering