Question

According to most scientists, cold fusion

will not be a practical source of energy on Earth.
would be a practical source of energy on Earth if it were less expensive.
will be a practical source of energy on Earth within the next few decades.
will always continue to be a practical source of energy on Earth.


I know the answer is not C or B

Answer 1

will not be a practical source of energy on Earth

Answer 2

Will not be a practical source of energy because it has failed many times in past trials such as in the experiments of Stanley Pons' and Martin Fleischmann. It will also be very expensive and solar and wind are better alternatives that are much cheaper and reliable to cold fusion currently without any further research.