The following table contains a partial list of countries, the continents on which they are located, and their respective gross domestic products (GDP) in U.S. dollars. A list of 125 countries and their GDPs is contained in the file GDPlist.
$$
\begin{array}{llr}
\text { Country } & \text { Continent } & \text { GDP (millions of US\$) } \\
\text { Afghanistan } & \text { Asia } & 18,181 \\
\text { Albania } & \text { Europe } & 12,847 \\
\text { Algeria } & \text { Africa } & 190,709 \\
\text { Angola } & \text { Africa } & 100,948 \\
\text { Argentina } & \text { South America } & 447,644 \\
\text { Australia } & \text { Oceania } & 1,488,221 \\
\text { Austria } & \text { Europe } & 419,243 \\
\text { Azerbaijan } & \text { Europe } & 62,321 \\
\text { Bahrain } & \text { Asia } & 26,108 \\
\text { Bangladesh } & \text { Asia } & 113,032 \\
\text { Belarus } & \text { Europe } & 55,483 \\
\text { Belgium } & \text { Europe } & 513,396 \\
\text { Bolivia } & \text { South America } & 24,604 \\
\text { Bosnia and Herzegovina } & \text { Europe } & 17,965 \\
\text { Botswana } & \text { Africa } & 17,570
\end{array}
$$
a. Sort the countries in GDPlist from largest to smallest GDP. What are the top 10 countries according to GDP?
b. Filter the countries to display only the countries located in Africa. What are the top 5 countries located in Africa according to GDP?
c. What are the top 5 countries by GDP that are located in Europe?