Which disease is caused by bacteria and transmitted through coughing or sneezing?

The correct choice is based on the understanding of tuberculosis, which is indeed caused by bacteria—specifically, the bacteria Mycobacterium tuberculosis. It primarily affects the lungs but can also impact other parts of the body. The key factor in the transmission of tuberculosis is that it spreads through the air when an infected person coughs, sneezes, speaks, or even sings, releasing droplets that can be inhaled by others.

In contrast to bacterial infections, pneumonia can be caused by various pathogens, including bacteria, viruses, and fungi, and while it can be transmitted in some forms, the emphasis on the specific transmission method in this question points toward tuberculosis as the primary concern. Asthma is not an infectious disease but rather a chronic inflammatory condition of the airways, often triggered by allergens or irritants, and flu is caused by viruses rather than bacteria. Thus, while there are infectious diseases that can be spread through respiratory droplets, tuberculosis is the clear choice due to its specific bacterial cause and mode of transmission.