According to studies regarding a nuclear attack, what percentage of people would likely survive the initial blast and heat effects?

The correct answer reflects findings from various studies regarding civilian survival rates in the event of a nuclear attack, which suggest that a significant portion of the population, particularly those not in close proximity to the blast epicenter, might survive the initial explosion and heat. Reports indicate that, depending on the circumstances, tens of millions of people could survive the initial effects due to factors such as distance from the blast, urban versus rural locations, and the availability of shelter. While there are many variables that can influence survival rates, including the size of the nuclear weapon and preparedness of the population, historical analysis often leans towards a higher survival estimate when considering a larger geographical area with significant population density.