I think its A but I'm not sure.
Non-native I believe that is the answer
Answer:
The first line of defence (or outside defence system) includes physical and chemical barriers that are always ready and prepared to defend the body from infection. These include your skin, tears, mucus, cilia, stomach acid, urine flow, 'friendly' bacteria and white blood cells called neutrophils.
Explanation: brainlieast...?
Awnser is d hope this helps
None of the above is correct.