On a string, as shown, two wave pulses move with equal speed of 8.0 cm/s towards each other. At the start of the observation, the pulses are 20 cm apart between their peaks. Draw the wave pulses' positions at t = 1.0 s, t = 1.5 s, and t = 2.0 s.

• A.
• B.
• C.
• D.

Answer: (D)