I'm not 100% sure... but I would say B.
Answer:
Humans produce too much carbon dioxide, and because of the chemical composition of water, more specifically, the water in the ocean, it is inclined to absorb it, thus making it acidic. Furthermore, human waste contributes to the acidity of the oceans.
I don't know your options, but there is one clear cause and effect relationship between the two:
As the agricultural methods advanced, people were more productive creating food. This means that not everyone had to engage in farming! And this allowed specialization for other jobs, just as smiths, which typically live in the cities.
Answer: OK but what's the question
Explanation:
