Lactobacillus acidophilus (below) is a probiotic microorganism typically found in the human small intestine. It has a cell wall made of peptidoglycan. It aids in the process of digestion and can commonly be obtained through sources such as acidophilus yogurt.

A microscopic image of lactobacillus acidophilus.

Which characteristic proves Lactobacillus acidophilus is from the specific kingdom Eubacteria?
It is multicellular.
It has a cell wall.
It is a microorganism.
It has peptidoglycan.