Which of the following represents a short run production story?

Over the last $10$ years, FreshFood, a grocery company, opened $20$ new stores and expanded to $3$ states.

Paula hires an additional worker for a night shift to increase production on their existing packaging assembly line.

T$.$ Motors is redesigning their production process to take advantage of technology and will open a new plant in $5$ years.

We should also introduce a critical concept: marginal product. Marginal product is the additional output of one more worker. Mathematically, Margir the change in total product divided by the change in labor: