Ultrasound exceeds human hearing range of 20 Hz to 20 kHz

Steps:

• Recall human audible frequencies: 20 Hz to 20 kHz.
• Define ultrasound as sound above 20 kHz.
• Check each range for complete overlap with ultrasound only.
• Confirm D starts at 30 kHz, fully above 20 kHz.

Why D is correct:

• Ultrasound is defined as frequencies above 20 kHz; D (30 kHz - 300 kHz) lies entirely in this range per standard acoustic definitions.

Why the others are wrong:

• A: 30 Hz - 3 kHz includes low audible frequencies below 20 kHz.
• B: 300 Hz - 3 kHz consists entirely of audible mid-range frequencies.
• C: 300 Hz - 30 MHz spans audible sounds up to 20 kHz and beyond.

Final answer: D