Read the passage about energy use in Dallas, Texas, from the US Department of Energy. During the past five decades, Dallas’s population has nearly doubled—growing from 679,000 in 1960 to more than 1.2 million people today. To support this rapid growth, develop a sustainable community and reduce Dallas’ impact on the electrical grid, the city created the Green Dallas Initiative with support from the Energy Department’s Energy Efficiency and Conservation Block Grant (EECBG) Program. Using some of its EECBG funds, Dallas focused on improving the energy efficiency of 248 city-owned buildings, totaling 3.3 million square feet. Following energy audits, the city made energy efficiency improvements that included upgrading to energy-efficient indoor lighting at more than 150 buildings and installing digital HVAC controls—technology that allows the city to monitor energy use and continuously adjust the systems to increase efficiencies and reduce energy consumption—in 100 city-owned facilities. Which best explains why Dallas has needed to find ways to reduce energy consumption?
A. Dallas’s population has grown as people have moved from the Rust Belt to the Sun Belt.
B. Dallas has run out of ways to create renewable energy and must use new sources.
C. Dallas has lost population and must reduce energy costs due to lost tax revenues.
D. Dallas’s federal funding is tied to a requirement that it reduce energy use by 50 percent.