The correct answer is A) countries in dark blue.
According to the map, the countries considered highly developed are the countries in dark blue.
The countries colored in dark blue have the highest Gross Domestic Product (GDP), which mean it is the sum of the market values, prices, and products and services produced in a specific country in one year.
As we see on the map, the most high-developed countries of the world are the United States, Australia, Canada, Great Britain, France, Germany, Switzerland, Norway, Denmark, Sweeden, the Arab Emirates, Japan, and New Zeland.