Which of the following differentiates christopher columbus from bartolomeu dias?

I will give you some information about these people…maybe it will helps you.

Bartolomeu Dias in search of a sea route to India in 1488 the first European to round the south Africa, discovered the Cape of Good Hope and reached the Indian Ocean. He was among the first Portuguese to set foot on the land of Brazil.

Columbus - Spanish explorer, in 1492 discovered for the Europeans to America, thanks to the expedition equipment Catholic Kings.Columbus was the first authentically known travelers crossed the Atlantic Ocean in the subtropical and tropical belt of the northern hemisphere and the first European to go to the Caribbean. He opened and laid the foundation for the study of South and Central America, including the continental part and the surrounding archipelagos.

answer: the time zones used to be whatever the local authority wanted them to be. one town might have 6am whenever the sun came up and another town had 6am 10 minutes later.  

the trains had a hard time when their orders said to be at a certain point at 6am.  

6am, but who's 6am.  

the railroads got together and set the time zones more or less along the longitude lines across the country.

explanation: