I think the correct answer would be the second option. The group of archaebacteria would be found on the lowest branch of a phylogenetic tree of all life. Phylogenic trees are illustrations of a hypothetical evolution of the organisms and its relationship with the other organisms. From the listed options, the archaebacteria is most likely to be the most basic and simplest life form. It should be placed before the other options so at the lowest branch. This illustration is being used by scientists to describe how evolution and the connection of the organisms came about. It sometimes called as the tree of life.