Final answer:
The growth of the world's human population is mainly due to improved healthcare resulting in lowered mortality rates and increased survival of children. This decrease in deaths and an increase in birth rates have led to an exponential growth pattern. Economic stability and education also contribute to changes in population dynamics.
Step-by-step explanation:
One of the key factors leading to the current growth patterns among the world's human population is C) Improved healthcare. Advances in public health, sanitation, medication, and vaccines have allowed for a significant decrease in mortality rates, especially in developed countries. Additionally, the advent of antibiotics has greatly reduced the deaths caused by infectious diseases, one of the historical limiters of population growth.
For all of these reasons, death rates fell, particularly in children, which increased the likelihood of many more children reaching adulthood, and as a result, birth rates also increased. The widening gap between birth and death rates spurred a rapid acceleration in human population growth. It's also worth noting that as countries become economically stable, a demographic shift occurs, leading to a decrease in birth rates thanks to economic security and education.