Which of the following is the best example of step migration?
a. movement from a harsh climate zone to another climate zone
b. migration from one continent to another
c. migration from one nation to another
d. movement from a rural area to a larger town, and then to a metropolis

d. new methods of assembly are introduced.

explanation:

this allows for the goods to be made on a larger scale. not faster because now it is shown to be made better, hence the greater productivity in the question. it is calling for something new to be introduced.

italy:

classic, nostalgic, romantic and beautiful. no place better than italy or sicily.