Which of the following diseases is associated with a bio-safety level 3 agent?

Tuberculosis is associated with a bio-safety level 3 (BSL-3) agent because it is caused by Mycobacterium tuberculosis, which can be transmitted through airborne particles. BSL-3 is a classification used to indicate that the pathogens handled in that environment can cause serious or potentially lethal diseases through inhalation and thus require specific control measures to prevent their spread.

In a BSL-3 laboratory, specialized ventilation and filtration systems are in place, along with personal protective equipment for those working with these pathogens, to ensure safety. This level of containment is necessary to minimize the risk of infection, as tuberculosis can easily spread within populations if safety protocols are not diligently followed.

Other options do not fall under BSL-3 classifications. The common cold is caused by less virulent viruses that are typically managed under lower biosafety levels. Chickenpox, while contagious, is not classified as a high-risk pathogen requiring BSL-3 conditions. Food allergies are not caused by infectious agents but rather by immune responses to certain foods, thus are not classified under bio-safety levels at all.