If Some Current Trends and Energy Strategies Continue and Succeed

If some current trends and energy strategies continue and succeed over the next few decades,in fifty years you might be able to say that you witnessed the shift from

A) an energy-consuming economy to an energy-producing economy.
B) a wind-driven economy to a solar economy.
C) an unsustainable fossil-fuel-driven economy to a sustainable hydrogen economy.
D) a renewable energy- driven economy to a clean-burning natural gas economy.