(a) The requirement is to describe the effect of an improvement
in technology that leads to increased worker productivity.
If the cost of producing a good declines, more will be supplied
at a given price. Therefore, the supply curve will shift to the
right and answer (a) is correct. Answer (b) is incorrect because a
shift to the left would result in decreased supplies. Answer (c) is
incorrect because price would not increase, and answer (d) is
incorrect because wages would not necessarily increase.