The second alternative is correct (B).
The literacy rate of a country is an indicator that tells a lot about the country's situation. Countries with lower literacy rates are usually poorer, which makes sense.
Education is the tool that develops people and countries. People with a standard of education are usually more productive workers. Productivity, in turn, is linked to the country's efficiency in the production of goods and services that make up the GDP. Thus, there is a connection between literacy rate and GDP.
In this example, Mozambique has a small GDP because the country's illiteracy rate is enormous. The opposite occurs in South Africa, the most developed country on the African continent, where the literacy rate is higher.
