Invertebrates have only nonspecific immunity which means

It means two things. One is that it attacks all foreign bodies, it's not specific to just one type of foreign bodies, and the other is that it's inborn and innate, meaning that you have a defense mechanism since birth, it's not aquired during life. If you're born without it you have to live in a bubble more or less.

C

Explanation: This would actually have a negative effect, if we were to lower natural gas prices in the community, it would mean more usage of natural gas (a fossil fuel).