Welding Has Changed Dramatically Over the Last Decade with More

Welding has changed dramatically over the last decade with more welding jobs dependent on the use of computers. This change increased the demand for welders with computer skills and decreased the demand for welders who lack these skills and is an example of when technology is a ________ to a high-skilled job and a ________ to a low-skilled job.

A) complement; substitute
B) complement; complement
C) substitute; complement
D) substitute; substitute