Which of the following bacteria causes botulism?

Clostridium botulinum is the bacterium responsible for botulism, a serious illness that results from toxins produced by this organism. This bacterium thrives in low-oxygen environments, such as improperly canned or preserved foods, where it produces a potent neurotoxin that can cause paralysis. Understanding the context of botulism is crucial because it highlights the importance of food safety practices, such as proper canning techniques and recognizing conditions that promote the growth of this bacterium.

The other options, while also related to significant health issues, do not relate to botulism. For example, Bacillus anthracis is the causative agent of anthrax, Clostridium tetani leads to tetanus, and Clostridium difficile is associated with antibiotic-associated diarrhea and colitis. Each of these pathogens has unique mechanisms of action and effects on human health, reinforcing the significance of identifying the correct organism in relation to specific diseases.