Polarization requires transverse waves Steps:

• Identify wave types: Electromagnetic waves (A, B, D) are transverse; sound waves (C) are longitudinal.
• Recall definition: Polarization involves restricting vibration direction, possible only in transverse waves.
• Apply to options: Check if each wave's nature allows polarization.
• Conclude: Longitudinal waves like sound cannot be polarized.

Why C is correct:

• Sound waves are longitudinal, with particle vibrations parallel to propagation, preventing restriction to a plane as required by polarization definition.

Why the others are wrong:

• A: Radio waves are transverse electromagnetic waves, polarizable by antennas.
• B: Ultraviolet rays are transverse electromagnetic waves, polarizable despite solar origin.
• D: X-rays are transverse electromagnetic waves, routinely polarized in experiments.

Final answer: C