The passage states that an increasingly high level of education is probably a necessary, but not a sufficient, condition for the complex political systems required by advanced economic performance. This directly points to option A as the correct answer. Option B, while related to the initial conditions that allowed humanity to focus on education, is not directly mentioned as a condition for political systems. Option C, the competitive environment, is mentioned as a factor that pushed our ancestors to achieve their productivity potential, but it is not specified as a condition for political systems. Option D, the level of economic performance, is the result of having complex political systems, not a condition for their development. Therefore, the correct answer is A.