**Core Concept**
The intensity of sound perceived by the human ear depends on the distance between the sound source and the observer, following the inverse square law. This law states that the intensity of sound is inversely proportional to the square of the distance from the source.

**Why the Correct Answer is Right**
When a person speaks in a loud voice, the intensity of sound radiates outward in all directions. As the sound waves travel through the air, they spread out and decrease in intensity. According to the inverse square law, the intensity of sound is inversely proportional to the square of the distance from the source. Therefore, when the distance between the speaker and the listener increases, the intensity of sound reaching the listener's ear decreases. In this case, the speaker is 1 meter away from the listener, resulting in a lower intensity of sound reaching the listener's ear compared to a closer distance.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not take into account the inverse square law, which explains how the intensity of sound decreases with increasing distance.
* **Option B:** This option is incorrect because it suggests that the intensity of sound remains constant regardless of the distance between the speaker and the listener.
* **Option C:** This option is incorrect because it implies that the intensity of sound increases with increasing distance, which is the opposite of the inverse square law.

**Clinical Pearl / High-Yield Fact**
The inverse square law is a fundamental principle in acoustics that explains how sound intensity decreases with increasing distance. This principle is essential in understanding how sound behaves in different environments and is crucial in fields such as audiology, speech therapy, and architectural acoustics.

**Correct Answer: B. The intensity of sound is inversely proportional to the square of the distance from the source.**