What is a physical barrier of communication?

C is the correct choice because a physical barrier of communication refers to any tangible obstruction that interferes with the transmission of messages between individuals. This includes environmental factors such as background noise, distance between communicators, or physical obstructions like walls or barriers. Noise in the environment can distract or disrupt the clarity of the message being communicated, thereby hindering effective communication.

In contrast, past experiences and stereotypes involve cognitive or psychological barriers, where individual perceptions and biases play a significant role in how messages are understood. Hidden agendas also pertain to interpersonal dynamics where a communicator may have ulterior motives or undisclosed intentions affecting the clarity and reception of their messages. While all options represent challenges to communication, only noise in the environment fits the definition of a physical barrier.