Which of the following lists industrial developments in proper chronol

Which of the following lists industrial developments in proper chronological order?

a. the completion of the first transcontinental railroad, formation of the first trust, formation of U.S.
Steel Corporation
b. the formation of U.S. Steel Corporation, formation of the first trust, completion of the first transcontinental railroad
c. the formation of the first trust, completion of the first transcontinental railroad, formation of U.S.
Steel Corporation
d. the formation of the first trust, formation of U.S. Steel Corporation, completion of the first transcontinental railroad
e. the formation of U.S. Steel Corporation, completion of the first transcontinental railroad, the formation of the first trust

ANSWER
A