The correct answer is B. Somalia
Step-by-step explanation
According to the graph, the country that most needs to improve its educational system is Somalia because there, twenty-three percent of the population is linked to primary education, while the other countries have higher percentages of their population related to the education, for example, Japan with one hundred percent, the United States with ninety-two percent and South Korea with ninety-eight percent. Additionally, a low primary school enrollment shows only a small percentage of the population has access to education and therefore, the education should be improved to guarantee everyone or at least the majority of the population has access to it. So, the correct answer is B. Somalia