“I could get TB if I come in contact with blood from an infected person.”
“I can share a cup of coffee with someone who is infected with TB.”
“I could get TB if I inhale infected droplets when an infected individual coughs.”
“I need to refrain from shaking hands with an infected person.”
Number 3 is correct.
TB bacteria is spread through the air from one person to another. When a person breathes in TB bacteria, the bacteria can settle in the lungs and begin to grow. TB is not transmitted through blood, sharing a cup of coffee, or shaking hands with an infected person.