What Was the Core Concept of Social Darwinism

What was the core concept of Social Darwinism?

A) The human race was driven by an unending economic struggle that would determine the survival of the fittest.
B) Genetics provided the mechanism by which favorable characteristics are passed on to future generations.
C) Darwin's evolutionary theory could best be proved by a careful examination of the vast amount of numerical data collected by governments in recent decades.
D) Gustav Le Bon was correct in asserting that strong, charismatic leaders could easily manipulate mass crowds.