I actually did the math for this a while ago. In order to install solar panels to every house in America it would cost a one time payment of about 900 billion dollars. We spend 700 billion on fossil fuels each year so in two years it would already pay itself off them we'd actually profit from it. Even if you don't believe in global warming you can't argue with that.
Plastic building blocks are good for building molecules because of some useful properties which they possess. For instance, plastic are flexible, they can be easily manipulated and can be made into any shape, size and combination. They can also be produced using different colors. Because of these features, they can be used to build and to explain how molecules behave.
I believe the answer is A (it was on another Brainly question as well).
All of th above support the heliocentric theory.