Answer:
b. Production and demand decreased with increased oil usage.
Step-by-step explanation:
While coal had traditionally been the main source of energy in the United States, in the 1950s, oil began to surpass it. Moreover, while the use of oil has continued to increase constantly, the use of coal has declined in recent years. Another important change in energy use in the United States is that of renewable sources of energy, which have also increased in popularity in recent years.