Established on the east coast of what is today mexico this settlement was built by hernando cortez and he became its first governor despite spanish laws that did not allow land claims for explorers

Trench warfare was famous war technic which is used to protect a soldier from any opponent’s attack in the battlefield.  

Explanation:

Trenches are long narrow pits dug deep into the ground to protect one’s self from the chemical attacks that gets spread in the air. In the trenches the soldiers feel safe and the chemicals would get mixed in the air and trenches to an extent provided protection to the artillery and also gunfire attacks.  

But many trenches when found by their enemies, it were made to explode and this resulted in mass causalities and deaths. Trenches were infectious and the dampness in the soil made the foot of the soldiers get swollen and infected. Cholera, dysentery and yellow fever were common and death toll was huge due to these infections. Many soldiers suffered psychologically as they were exposed to continuous bombardments and explosions.

the answer wold be b) travel among nations should be regulated by an international organization