How are pathogens able to get past the body’s first line of defence?

Stomach acid kills bacteria and parasites that have been swallowed. Your urine flow flushes out pathogens from the bladder area. Skin, tears and mucus are part of the first line of defence in fighting infection. They help to protect us against invading pathogens

Explanation:

well, that's easy; the answer's c, "it reduces contamination of the water and substrate of the estuary."

i think that it is c, d, and e, hope this