Which statement is true?
a. a sustainable energy source is one that will not run out.
b. a sustainable energy source is one that does not cost very much.
c. a sustainable energy source is one with a high environmental cost.
d. a sustainable energy source is one that can be grown by farmers.

   A.A sustainable energy source is one that will not run out.

Explanation:  Sustainable energy sources are those that do not depend on the amount of natural resources, that is, they will not disappear, and they belong into desirable sources, especially nowadays. This includes wind energy, solar energy,  geothermal energy, hydropower, biomass energy, and is desirable due to increasing pollution, ozone depletion and climate change arising from the use of fossil fuels.

to protect the united states' role as a world leader, president truman wanted to prevent the soviet union from spreading communism beyond its post-world war ii boundaries. he declared that the united states must assist any nations struggling to prevent a communist takeover.

brainliest is someone you pick by simply clicking a button. it only shows up if there are two people that answered your question, then you decide who answer more accurately with detail and explanation and you give that person the title "brainliest".

i hope this your understandings.