Their meeting was rather boisterous.

The correct answer is C. noisy.

Boisterous means loud and noisy, especially in a way that is cheerful and exciting. The other options are:

• Quiet: not making or producing any noise.
• Businesslike: showing or having a serious and efficient manner.
• Calm: not showing or feeling any strong emotions, especially fear or anger.

In the context of the question, it is most likely that the meeting was noisy because people were talking and laughing loudly. It is possible that the meeting was also businesslike, but this is not the most likely interpretation of the word “boisterous.”