Welding Is a Dangerous and Dirty Job

Welding is a dangerous and dirty job.Suppose someone developed new machinery that made welding safer and cleaner at the same time it made welders more productive.What would we expect would happen to the wages of welders

A) They would rise since labour productivity increases.
B) They would fall since there is less demand for welders.
C) They would rise if the change in the demand for welders is greater than the change in the supply of welders.
D) They would fall if the change in the demand for welders is greater than the change in the supply of welders.