The answer is the first option- "A-T"
Magma is basically molten rock but INSIDE the earth, Lava is Molten rock that is no longer under the crust, and is on the surface (like lava from a volcano
Solar power would, without doubt, be the most efficient type of power plant to build in this specific location. This is due to the fact that solar power produces no pollution in an environment. Also this type of alternative energy fits this communities resources due to the fact that the community receives primarily sun , a huge component in solar power, and little cloud coverage only increases the sun's power that much more. On the other hand, biomass needs things like wood, crops and alcohol fuels to burn in order to produce energy, some of which are not viable in this type of community because a place with little to no irrigation sources and an abundant amount of sunlight would be hard to produce any kind of natural aspect. Lastly, hydroelectric energy would not be a efficient of even viable choice because this community has no natural water available at hand to use for this alternative energy to function, and hydroelectric works primarily on a water storage.