Answer:
C. Clostridium and Bacillus.
Step-by-step explanation:
Bacillus and Clostridium are the gram-positive bacteria and form endospores. Endospores are the resistant dormant structures formed by some gram-positive bacteria.
These bacteria form the endospores within their vegetative cells. The endospores are highly resistant to environmental stress conditions and make these bacterial genera the dangerous pathogens.