Which of the following is not a barrier to economic development?

a. foreign debt

b. political stability

c. widespread disease

d. low levels of social welfare

Political stability is not a barrier to economic development - the correct answer is b) !

In fact, political stability supports economic development, for example by removing the fear of potential investors.

All other options are a barrier, for example foreign debt means that rather than investing, a country has to pay it back.