A blast in a major oil pipeline makes the world price of a barrel of oil rise from $50 to $100. Prior to the blast, world demand for oil was 100 million barrels per day. The world price elasticity of demand for oil is $-0.2$. What is the new worldwide demand for oil (barrels per day) following the blast?
- A20 million
- B80 million
- C90 million
- D120 million