What is the most significant reason for the dramatic increase in expected life span over the last 100 years?

The development of antibiotics and immunizations.

Explanation:

there are conflicting perceptions. what cannot be denied is that despite a long history of discrimination, they finally chose to bow out in grace and handed over power to the majority. it was a painful experience for them to part with their prerogatives and some chose to leave the country. however, they did decide to bite the bullet and go through the process with minimum obstructions.

presently, whites are still a force to reckon with. they are well educated, have technical and business expertise, they understand imperatives of good governance and are responsible for keeping south africa connected with developed countries. despite a bitter history, they are useful team members of the south african team.

answer; /// i believe that the correct answer is ; /// renaissance,printing press, age of exploration and protestant reformation;