On April 20, 2010, an explosion on the Deepwater Horizon Macondo oil well drilling platform released 4 million barrels (636,000 cubic meters) of oil into the Gulf of Mexico. It took scientists and engineers nearly three months and several different attempts to cap the well. The Macondo oil well was located 1524 m (5000 feet) below the surface of the water, about 80 km (50 miles) off the coast of Louisiana. The spill affected 2113 km (1300 miles) of shoreline along the coasts of five states. Most crude oil contains 84–87% carbon by weight. Scientists have not yet fully assessed the environmental impact of the accident. Reducing our dependence on petroleum is a difficult task, so policy makers are organizing it into smaller, simpler problems that can be solved more easily. Choose two of the solutions below that may help reduce our dependence on fossil fuels.
a
Researching alternative fuels to petroleum, such as ethanol.
b
Increasing taxes or fees to help pay for cleanup costs.
c
Requiring rooftop gardens to be built on all new buildings to reduce air pollution.
d
Developing transportation methods that do not require the use of petroleum products.