Answer:
A
Explanation:
I would say A is the best answer to this question. B and D do not apply to unicellular organisms because they are not made up of multiple cells, and we only see specialized tissues in animal species which are not unicellular (clade metazoa includes all animals with specialized tissues not including unicellular organisms). D doesnt make sense because mitosis doesnt occur in unicellular cells they reproduce via binary fission. C doesnt make much sense either because bacterial organisms can reproduce with extreme speed and their high speed of reproduction is one of the main reasons there is increasing antibiotic resistance. This process of elimination leaves A which is the most logical answer in my opinion.