Final answer:
The diseases requiring airborne precautions among those listed are TB and varicella, making the correct answer b. 1 and 2 only. Rubella requires droplet precautions rather than airborne.
Step-by-step explanation:
The diseases that require airborne precautions for prevention of their spread include tuberculosis (TB), varicella (chickenpox), and measles, but not rubella (German measles), which requires droplet precautions. To address the student's question:
- Tuberculosis is highly contagious and spread through the air when infected individuals cough, sneeze, or spit.
- Varicella, or chickenpox, is also an airborne disease and can spread through respiratory aerosols.
- Rubella, on the other hand, is primarily spread through respiratory droplets which are larger than those that transmit TB and varicella and generally require close contact with an infected person.
Therefore, diseases 1 (TB) and 2 (Varicella) require airborne precautions, while Rubella requires droplet precautions. The correct answer to the student's question is b. 1 and 2 only.