Answer:
Option A, Earthquake data is analyzed to determine if a tsunami is likely, and if so, warnings are sent out.
Step-by-step explanation:
Warnings for Tsunami can be detected by seismograph (a device that measures earthquake), which is essential for observing any kind of movement of the tectonic plates below the surface of ocean. Pre-determination of any such event helps in forecasting the calamity much before its onset and allows the concerned department of any city to send warning messages to the resident of the city , so that they can move to safer areas.
Hence, option A is correct