B the atm hehsjskkakajahhajajajajjajajajsjsjjsjsjsnsnnsns
Hydrogen is the smallest elements , with one potron and one electron .it is highly abundant no has unique and important chemicals properties .
C. earth's internal heat
See the parts of the word "geothermal": "geo" means that it is related to the earth, and "thermal" means it is related to heat.
I believe it is answer 2 and 4
