Wave properties during refraction Steps:

• Refraction bends the wave path when entering a new medium at an angle.
• Frequency remains constant as it is set by the source and unaffected by medium change.
• Speed changes due to differing densities and elastic properties of air versus water.
• Wavelength adjusts via the relation v = fλ, where v is speed and f is frequency.

Why B is correct:

• Speed varies with medium (slower in water), frequency stays constant, so wavelength changes to satisfy v = fλ.

Why the others are wrong:

• A: Frequency does not change across media.
• C: Frequency does not change; speed does.
• D: Frequency does not change.

Final answer: B