Developments in European culture fuelled by the Renaissance.
- Changes in the Christian religion fuelled by German Martin Luther.
- The race begins between Christian Europeans to find new trade routes to China for silk and Indonesia for spices as the Muslim Ottomans block the Mediterranean sea to all Christian shipping.English and other European Explorers.
500 years ago the English started exploring the world in sailing ships. (This was the first step to England creating a world wide empire.) The catalyst to explore at this time was the blockade of the Mediterranean sea in 1448 by the Islamic Ottoman (Turks) thus closing access to the only known trade route to the east (India and China.)
The correct answer is option D. "Companies replaced hand-operated brakes with air brakes on trains". The development of air brakes on trains was a significant improvement of railroad safety. Air brakes function much more faster than hand-operated brakes, because hand-operated brakes required that the brakemen turned the brakes in one car and jump to the next to set the brakes on, and so on.