Ever since Giselle's company developed its new product ten years ago, Giselle has managed its production with little turnover in workers. During that time, the company's average cost has fallen by $30\%,$ due to the refinement of its producti methods, thereby achieving greater efficiency. Other rival companies have not achieved such low costs. The advantage tha

Giselle's company now has over rivals stems from achieved through

a marginal cost reduction; long$-$term production

a key input price reduction; unique cost advantages

a unique cost advantage; learning by doing

mass production; key input price reduction