B. Saudi Arabia
Explanation :The United States is the top oil-producing country in the world, with an average of 17.87 million b/d, which accounts for 18% of the world’s production. This is up from the 15.6 million b/d in 2017.
Total world crude oil production increased sharply in 2018 by 1.213 million barrels/day (mb/d), or 1.6%, as compared to 2017, to reach 75.78 mb/d, marking a historical high and the highest annual growth since 2015. OPEC crude oil production declined y-o-y by 415,000 b/d, or 1.3%, while crude production by non-OPEC countries grew by 1.628 mb/d, or 3.8%. In 2018, the top three crude oil producing countries were the United States (10.96mb/d), Russia (10.53mb/d) and Saudi Arabia (10.32mb/d).