How does the body make it difficult for a pathogen to reach a part of the body that can cause disease

thats a little if u want the answer just look it up on google thats what i do haha : )

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

that's it!

if you need further assistance, let me know: )

~ trueboss72

c) should be the answer.