I believe the answer is earthquakes.
Answer:
The Panama canal
Explanation:
Opened in 1914, the Panama canal allows maritime traffic to travel between the Pacific and Atlantic oceans very rapidly through a system of locks (2 on the Pacific side, one in the Atlantic side), and the boats pass through an artificial lake crossing the whole country of Panama.
It takes just a few hours to cross from one side to the other, while it would take weeks to go down to the tip of South America and back up.
In 2016, the canal opened new locks, that can receive larger boats.
Ok so the answer will be C
