Primary succession would occur
a. in a field
b. on an island just formed by a volcanic eruption
c. in an area after a forest fire
d. all of the above

sorry to break it to ya but no one can answer your question it's just

jk but i am serious about the part that most people cant answer it beacuse you did not mention the section you are talking about. but it would if you added some detail and were a bit more specific.

they had the law tat factories that produces smoke cannot be built near residential buildings.

building of proper sewage system was done to ensure that the waste is carried away from the humans so that they do not get diseases from it.

also they built water systems to provide water in those areas which are drought prone.

some inherited genetic mutations can be good for the offspring, so the answer is different genetic mutations cause many forms of cancer.