What would a "tumultuous" crowd likely be characterized by?

A "tumultuous" crowd is best characterized by noise and uproar because the word "tumultuous" conveys a sense of chaos, disturbance, or violent commotion. It suggests a situation that is lively to the point of being disorderly, often involving loud sounds and a lot of movement. This description aligns perfectly with the idea of a crowd being raucous and filled with activity, indicative of heightened emotions or conflict.

The other options suggest characteristics that are much quieter or orderly. Silence and contemplation, calm conversations, and uniformity and order describe situations that would be the opposite of tumultuous, as they imply a lack of chaos or upheaval. Thus, the choice of noise and uproar is the most fitting description for a tumultuous crowd.