How does a seismologist use the graph of time versus distance for seismic waves to find the location of an earthquake’s epicenter?

this is for earth and environmental science, it does not have that subject so i am sorry if this is the wrong category.

Which of the following types of stars is most likely to end up as a supernova? in graph a, the curve peaks at 800 nm, in the red section of the visible light spectrum. in graph b, the curve peaks at 550 nm, in the green section of the visible light spectrum. in graph c, the curve peaks at 450 nm, in the blue section of the visible light spectrum. in graph d, the curve peaks at 300 nm, in the violet section of the visible light spectrum. a b c d