Answer:
c.)natural
Explanation:
cotton, wool, and silk all grow themselves so they are natural
Um your question is very unclear lol
Common colds are caused by viruses and antibiotics only work in bacteria. Antibiotics work by targeting the different replication processes and functional characteristics of bacteria. Virus on the other hand are only active once they have invaded something to use as a host. Therefore it is more difficult to target the mechanisms of viruses because they are usually dormant and have different organelles than of bacteria.
I believe it would be the last one since it is from the national institutes of heath, and that it the most reliable source.
