I think BO or B, but BO has more chance.
The early hominid stages can be differentiated from one another based on the complexity of the tools used by these species. The tool evolved along with the evolution of the humans. The more the hominids evolved by more complex their tools became. The tools made by the earliest hominids were used to fish out the termites. These tool developed and became more widely used as the humans evolved.
Hence, the answer is 'by observing the complexity of the tools'.
SI is a base 10 standardized system. I hope this helped and if not I highly recremend talking to your teacher or a parent.
Heat/melting and pressure.
Mitosis and cytokinesis divide a parent cell into two IDENTICAL daughter cells
