What is the author’s opinion of geothermal energy?

A Geothermal energy has some disadvantages, but it is problably going to be used in the future

B Geothermal energy is source that should be explored further before large-scale production begins 

C Geothermal energy offers an opportunity to supply a significant amount of power in the future

D Geothermal energy should replace water power in the production of electricity for the United States