Of which domains are the prokaryotes members?
a. archaea and bacteria
b. archaea and eukarya
c. bacteria and eukarya
d. bacteria, eukarya, and archaea

The answer is a. Archaea and Bacteria.

According to the modern taxonomy, the highest taxonomic rank of organisms is a domain. The classification is based on differences of ribosomal RNA. There are three domains in the tree of life: Archaea, Bacteria, and Eukarya. Archae and Bacteria are Prokaryotes, unicellular organisms without a nucleus and organelles. Eukarya mostly includes multicellular organisms with a nucleus and organelles. 

Generally travels west to east but often shifts to north and south

Heatamount of salt . . .