Final answer:
Chlamydiae are the obligate intracellular parasites among the options provided. They have a unique life cycle and can only multiply within host cells.
Step-by-step explanation:
The obligate intracellular parasites mentioned among the options given are Chlamydiae. These are bacteria that can only survive and multiply inside the cells of a host organism. They lack a traditional peptidoglycan cell wall and have a unique life cycle, converting between elementary bodies (infectious form) and reticulate bodies (reproductive form) within the host cell. While viruses are also obligate parasites as mentioned in the context, the specific answer to this question lies within the given choices, making Chlamydiae the correct response.