Which of these is an advantage of hydroelectric energy
a. is available only in limited areas
b. reduce greenhouse-gas emissions
c. is expensive to build or maintain
d. harms aquatic organisms

B. reduce greenhouse gas emissions

Explanation:

The hydroelectric energy has its pros and cons as most of the energy production facilities do. One of the biggest advantages of the production of this type of energy is that it almost doesn't emit any greenhouse gases into the atmosphere. Considering the problem that the world is facing because of it, especially the climate changes and rising sea levels because of that, this is seen as a very big plus for any type of energy production. This has resulted in the building of more and more dams that produce hydroelectric energy, some of which have been made very large and very large energy production.

if you add everything up correctly you should get 69 i got this because 50 plus 19 is it