Answer :
Final answer:
The distance to the epicenter from a seismic station based on S-wave travel time requires knowing the velocity of the S-wave, which isn't provided in the question or references. Without this information, it is not possible to calculate the distance.
Explanation:
To determine the distance between the epicenter and the seismic station based on the travel time of the S-wave, which is given as 21 minutes and 50 seconds, you can use a standard travel time graph or a formula, if available. However, in this case, as the actual S-wave velocity is not provided in the question or the provided information, it is impossible to give a precise calculation or to select one of the options provided (a-d).
To solve such problems, typically, you would convert the time to seconds (21 minutes x 60 seconds/minute + 50 seconds = 1310 seconds), and then multiply by the S-wave velocity if known (for instance, S-wave travels x km/s, distance = 1310s * x km/s). But lacking the specific S-wave velocity, I cannot complete the calculation required to answer your question.
