Seismic waves
Step-by-step explanation:
An earthquake releases energy as shock waves, the so-called seismic waves, which ripple across the earth's surface. The seismic waves created as they move from the epicentre an earthquake vary.
(from Google)
That's we can solve by using a combination algorithm:
Answer: c 5 cm
Step-by-step explanation: 40 - 35 is 5 cm