Final answer:
The recommended distance to hold the mouthpiece of a phone from your mouth to avoid distortion or faintness is about 1 inch.
Step-by-step explanation:
To ensure clear communication and prevent voice distortion or faintness, the recommended distance to hold the mouthpiece of a phone from your mouth is about 1 inch (D). Holding the mouthpiece at this distance helps prevent the breath from directly hitting the microphone, which can cause sound distortion, and ensures that your voice is picked up clearly.