Which technological innovation do you believe has had the greatest impact on film and why?

Imagine this is 1979: If you were reading this article back then, chances are you would have read it on paper — with a printed newspaper or magazine in your hands. Today, you are probably reading it on a desktop computer, a laptop (or as a printout from either of these), or perhaps even on your Blackberry or iPhone. The pace of innovation has been so hectic in recent years that it is hard to imagine which innovations have had the greatest impact on business and society.

Answer (a) with a mirror like surface;