The bar graph in the following graphic represents fictional net exports in billions of dollars for five countries. Net exports are obtained by subtracting total imports from total exports; a negative net export means the country imported more goods than it exported. A horizontal bar graph titled Net Exports (Billions of dollars) has net exports (billions of dollars) on the x-axis, from negative 150 to positive 150 in increments of 60, and country on the y-axis. Spain, 20; Germany, 40; China, 120; Denmark, negative 30; United States, negative 110. What is the difference between the net exports from The United States and Denmark ? a. 70 billion dollars c. 90 billion dollars b. 80 billion dollars d. -140 billion dollars