Answer:A. Primary prevention
Step-by-step explanation:
Primary Prevention Techniques are used to eliminate whatever factors or situations that may lead to an infection through working with specialists in that field. This may include getting vaccinated , eating healthy and exercising and abstaining from smoking.
The focus of primary prevention is to prevent an infection or injury before it actual happens.
Actions like minimzing or eliminating exposure to potential factors that may cause that infection or injury , eliminating unhealthy behavior.
Actions are taken before people are infected.
thus eliminating exposure to second-hand smoke is a primary prevention example.