How Is the Distance to the Epicenter of an Earthquake

How is the distance to the epicenter of an earthquake determined using a seismograph?

A) How hard the seismograph needle swings back and forth is noted.
B) Travel time is clocked and then compared to the reported time of the earthquake at the epicenter.
C) The arrival times of surface waves are noted.
D) The delay time between the P-wave and the slower S-wave is considered.
E) You cannot do this with a single seismograph.