Eubacteria is one of the 6 kingdoms. Eubacteria is also called as true bacteria and present in almost every where in any condition. Kingdom Eubacteria consists of nearly 5000 species that have been discovered date, and this number might increase in near future.
Lactobacillus acidophilus is a gram positive, rod-shaped bacteria present naturally in gastrointestinal tract of humans. It contains peptidoglycan in their cell wall which is one of the main characteristic of kingdom Eubacteria.
So, The correct answer for this question is (D)