<span>Political stability is not a barrier to economic development, so the correct answer is B. If something is stable, it means that it is in a good condition, and if it's in a good condition, it cannot be bad or preventing good things from happening. So B is a good thing, and cannot be a barrier to anything. Debts, diseases, and low levels of social welfare can be barriers, because they are indicators of bad conditions in a country. </span>
