World’s longest rail tunnel is in

a. Russia

b. Japan

c. Switzerland

d. China

ANSWER: Switzerland

Explanation:

In Switzerland, the world's longest and deepest rail tunnel, running under the Swiss Alps has been inaugurated.

The 57-kilometer long Gotthard Base Tunnel will connect northern and southern Europe and shorten travel time for many rail routes.

It overtakes Japan's Seikan tunnel, which measures 53.9 kilometres, as the longest rail tunnel in the world.