Answer:
A. and C. are correct
Explanation:
The maya's used their own form of hieroglyphs So A. is correct
And they used Astrology to predict stuff like solar and lunar eclipse and the movements of constellations So C. is correct.
Geothermal plateau. I'm only guessing, but since a lot of places use heat as energy it only makes sense.
D) To help former slaves succeed in post-Civil War America