I would say that D is the most important reason ie to monitor the location and magnitude of seismic activity to attempt to find patterns which may lead to the ability to predict the next earthquake in the world though individual seismic stations probably monitor more the seismic activity in their own country mostly though perhaps not exclusively.
You might recognize that a tsunami is approaching because the ocean tide begins to recede to an extremely low level.
Answer:
George Washington
On April 30, 1789, George Washington, standing on the balcony of Federal Hall on Wall Street in New York, took his oath of office as the first President of the United States.
