Question

which type of barrier are coughing and sneezing?
○ psychological
○ chemical
○ biological
○ physical

Explanation:

Coughing and sneezing are physical actions that help the body expel foreign particles or pathogens, acting as a physical barrier in the immune system. Psychological barriers relate to mental factors, chemical barriers involve substances like enzymes or acids, and biological barriers refer to living organisms (like beneficial bacteria). So coughing and sneezing are physical barriers.

Answer:

D. physical (assuming the options are labeled A to D as A. psychological, B. chemical, C. biological, D. physical)