The was one of the world’s first subway systems, opening in 1863.
a. los angeles metro
b. london underground
c. paris metro
d. chicago el

The correct answer is B. The London Underground was one of the world’s first subway systems, opening in 1863.

Explanation:

The London Underground is a public electric rail transport network that runs both underground and below ground throughout the Greater London area. It is the oldest transport system of this type in the world, as it entered into operation on January 10, 1863.