Final answer:
Price is the factor that is NOT held constant along a given supply curve for a good, as changes in price result in movements along the curve, while changes in production costs, technology, or taxes would shift the curve entirely.
Step-by-step explanation:
In analyzing the elements that determine the placement of a supply curve, it is essential to maintain certain factors constant to isolate the effect of the good's price on its supplied quantity. By convention, we hold factors such as the cost of factors of production, technology, and taxes constant along a supply curve, under the assumption of ceteris paribus ('other things being equal'). Hence, the factor that is NOT held constant along a given supply curve for a good is the good's price. Price is the variable that corresponds to movements along the supply curve, while the other factors, if changed, would result in a shift of the supply curve.