Which of the following issues was the worst problem caused by early surface rail systems?

A.

They were too expensive for most people.

B.

They created the first major pollution problems in cities.

C.

They created gridlock with other traffic on crowded city streets.

D.

They were incompatible with rail systems between cities.

The surface rail system is one of the transportation that is common nowadays. This is used to transport both passengers and goods from one place to another through rails or also known as tracks. Upon the early surfacing of this kind of transport system, the worst issues that arose was that they were incompatible with rail systems between cities. The answer is option D.