Answer:
Uracil
Explanation:
Uracil is a base only found in RNA which is different from DNA. Instead, DNA has guanine.
B... These microbes are the foundation for life in hydrothermal vent ecosystems. Instead of using light energy to turn carbon dioxide into sugar like plants do, they harvest chemical energy from the minerals and chemical compounds that spew from the vents—a process known as chemosynthesis . (I got this off the web hope it helps)
Option three should be correct