please help me with this

How did the railroad system contribute to Georgia’s economy in the past, and what is its role today?
A
Railroads were important during the nineteenth and early twentieth centuries, as a method of exchanging goods, but have been largely replaced by the other three systems.
B
Railroads were the most efficient transportation system until the 1850’s, when they were replaced by the interstate highway system.
C
All goods arriving at the deepwater port in Savannah have traveled by railroad to the rest of the country since the nineteenth century.
D
Railroads have contributed more to the exchange of goods than the other transportation systems and are still the most active today.
i