The use of the bar code, or Universal Product Code, which was created in part to enable supermarkets to process customers at a faster rate, has expanded beyond supermarkets to other retail outlets and have become readily accepted despite some initial opposition when it was first introduced in 1974.

A) have become readily accepted despite some initial opposition when it was first introduced in 1974

B) has become readily accepted despite some initial opposition when they were first introduced in 1974

C) have become readily accepted despite some initial opposition when first introduced in 1974

D) has become readily accepted despite some initial opposition when the bar code was first introduced in 1974

E) bar codes have become readily accepted despite initial opposition when it was first introduced in 1974