Which groundbreaking product design feature did Steve Jobs initially oppose before it became a defining element of Apple's iPhone success?

In the world of product design, some innovations completely transform how we interact with technology. These breakthrough moments often involve rethinking fundamental assumptions about user experience. This trivia question focuses on a pivotal design decision that changed the trajectory of a now-ubiquitous product. Test your knowledge about the design evolution of everyday items that have become essential parts of modern life.

This is a live public trivia poll on AIPolls.Net. Vote and see real-time results.

The multi-touch screen interface
The App Store concept
The elimination of a physical keyboard
The use of gorilla glass for the display