Answer the following question given this paragraph: 

Seismograms contain a lot of information about an earthquake: its strength, length and distance. Wave height used to determine the magnitude of the earthquake. The seismogram shows the different arrival times of the seismic waves ( Figure below ). The first waves are P-waves since they are the fastest. S-waves come in next and are usually larger than P-waves. The surface waves arrive just after the S-waves. If the earthquake has a shallow focus, the surface waves are the largest ones recorded.


Q: What three parameters do seismographs measure?

 Choices:

- height, width and distance

- aging , length and distance

- trouble , length and distance

- strength, length and distance

A:
strength, length and distance
