What is the most significant reason for the dramatic increase in expected life span over the last 100 years? * better living habits improved surgical techniques the development of antibiotics and immunizations a decrease in the number of people living in poverty

You didn't give the options btw

Few days to several months depending on the severity of the stroke ;

The answer you're looking for is washing your hands. "at this late date, we all expect our doctors to wash their hands before examining us or performing an operation in order to prevent the spread of infection. surprisingly, physicians did not begin to acknowledge the lifesaving power of this simple act until 1847.it was then that dr. semmelweis began exhorting his fellow physicians at the famed vienna general hospital (allgemeines krankenhaus) to wash up before examining women about to deliver babies. his plea was far more than aesthetic; it was a matter of life and death and to prevent a deadly malady known as “childbed” or puerperal (from the latin words for child and parent) fever." 

When someone is overly controlling.i hope this .