When studying water wave interference, one can observe that destructive interference takes place if the waves are out of phase by 1/2 wavelength or 180°. Explain why a 180° phase difference corresponds to 1/2 wavelength in the context of water waves.

• A. Because 180° represents a full wavelength and thus completes a full wave cycle.
• B. Because 180° phase difference means one wave is half a wavelength ahead or behind, causing cancellation.
• C. Because 180° phase difference indicates the waves have identical frequency and amplitude.
• D. Because 180° is the phase difference where both waves reach maximum amplitude at the same time.

Answer: (B)