Polarization depends on wave type

Steps:

• Recall that polarization is the orientation of wave oscillations perpendicular to the direction of propagation.
• Identify radio waves as electromagnetic waves, which oscillate transversely (electric and magnetic fields perpendicular to travel).
• Identify sound waves as mechanical waves in air, which oscillate longitudinally (particles move parallel to travel).
• Conclude that only transverse waves allow restriction of oscillation direction, enabling polarization.

Why B is correct:

• Transverse waves have oscillations in a plane that can be aligned or filtered (e.g., by a polarizer), per the definition of polarization in wave physics; longitudinal waves lack this directional variability.

Why the others are wrong:

• A: Frequency affects wavelength but not the ability to polarize, which is structural.
• C: Vacuum travel relates to medium requirements, not oscillation type for polarization.
• D: Speed differences arise from medium and wave nature but do not determine polarizability.

Final answer: B