Complex structures called fruiting bodies are a characteristic of A. Clostridia. B. myxobacteria. C. Streptomyces. D. lactic acid bacteria.

myxobacteria

Explanation:

Myxobacteria are also known as slime bacteria that are a group of gram-negative bacteria. Myxobacteria are known to form fruiting bodies under the conditions when nutrients are scarce. Fruiting bodies are nothing but an aggregation of the myxobacteria which can take different shapes and forms. By associating within fruiting bodies the myxobacteria benefit by resuming the cellular growth in a swarm fo bacteria rather than as isolated cells. The myxobacteria are found as rounded thick-walled organisms within these fruiting bodies.