单选题 This doesn't mean that wind and solar, which currently provide less than 1 percent of the world's primary energy, will replace fossil fuels, which provide 82 percent. In fact, while companies like BP and Shell are cutting back on commercial projects in wind and solar, Big Oil is taking a closer look at how they might be used to increase efficiency internally, or to flee up increasingly profitable fossil fuels, like natural gas, for commercial sale. For example. Valero is building windmills to power refineries, and Chevron is using solar power to make steam to extract tough-to-reach oil. When you consider that the top 15 oil and gas companies have a market capitalization of $1.9 trillion, it's clear that these firms themselves have the potential to be major renewable customers.
Big oil is thinking of using wind and solar

• A. to free up fossil fuels for commercial sale.
• B. to replace fossil fuels for commercial sale.
• C. to increase efficiency of fossil fuels use.
• D. to reduce harm to the environment.