Both A and C could be correct, but i'd go with A.
Answer:
particulate matter.
Explanation:
Pollution can be defined as the physical degradation or contamination of the environment through an emission of harmful, poisonous and toxic chemical substances. Particulate population is a form of pollution that is responsible for the degradation of the environment.
Particulate matter is also referred to as particle pollution or atmospheric aerosol particles and it can be defined as a complex microscopic mixture of liquid droplets and solid particles that are suspended in air. Other forms of particle pollution includes space debris and marine debris.
Some examples of particulate pollution are dusts, soot, dirt, smoke, etc.
Basically, various anthropogenic activities such as construction and agriculture are primary sources of particulate matter because they're capable of causing particle pollution on their own. The other sources of particle pollution is the secondary source which includes factories, cars, trucks, etc.
I think it is description
This is a case of "negative reinforcement". The term was created by B.F. Skinner, and it is about not doing something in order to avoid suffering or pain (physical or psychological). A good example of negative reinforcement can be seen in the movie "A Clockwork Orange", directed by Stanley Kubrick. The main character goes to a correctional facility where he's forced to watch violent movies while experiencing an unimaginable sensation of nausea. The goal of the institution was to turn him into a non-violent individual by conditioning his brain to associate violence with feeling sick to his stomach. In fact, after such experiment he wasn't even able to enjoy Beethoven's music anymore, since it was played throughout the whole "therapeutic" movie sessions. In Herbie's case, he could no longer eat his daily chocolate chip cookies, since he didn't want to get nauseated again. It doesn't mean he would necessarily feel that way if he actually had the cookies, but he refused to eat them anyway, since he'd already been negatively reinforced not to eat them.
