Anne was observing a cell under a microscope which was undergoing binary fission. which type of cell was anne observing? 1 eukaryotic animal cell 2 eukaryotic plant cell 3 prokaryotic cell

3 is the answer.  

Binary fission is a type of asexual reproduction and is the most common method of reproduction in prokaryotes. It may occur in some unicellular (single- celled) eukaryotes..

Eukaryotes use sexual recombination during reproduction to create or generate genetic variation and thus the resulting offspring will have a mixture of the parents' genetic characteristics. 

Prokaryotes on the other hand will simply produce clones of themeslves through binary fisson. After the process of replicating its own genetic material, the  prokaryote  simply divides into two daughter cells that are almost identical in size and that concludes the process.