Which of the following best describes the steps of figuring out the casualty of earthquakes？

A. Registering the earthquake→calculating the details of the earthquake→predicting the loss of life and money.
B. Gathering information about the building→calculating the details of the earthquake→predicting the loss of life and money.
Calculating the details of the earthquake→gathering information about the building→predicting the loss of life and money.
D. Reporting the earthquake→gathering the information→predicting the loss of life and money.