Question $35$

Which of these would result in a movement along the supply curve, rather than a shift in the supply curve?

an influx of people, including some who are plumbers, into a region

an increase in the number of plumbing apprenticeship programs

a government infrastructure project that includes laying new plumbing pipes in many cities, pushing up the prices plumbers charge

the development of high$-$definition cameras used to locate obstructions in plumbing systems