<span>C. 3
Due to the different speeds of P and S waves, a single seismometers can determine the distance to an earthquake. So, for a single station, the localization is any point on a circle around the station. With 2 stations, you'll have two circles that intersect at two points. The 3rd station is needed in order to determine which of the 2 points is the actual earthquake.</span>
OR! Because one OR the other (or both, as this is not an exclusive or) needs to be present in the search result.
Answer:
Deleting files and etc on your computer.
