Many commuters grab a cup of coffee and drink it during their ride to work. so someone invented specially shaped cups that don't tip and lids with sip openings that close and don't spill. which of these innovative ways of thinking best fits this situation?

The best one is a study which explores the ways through which the existing product can be improved.

This can be related to its function, in a way that only enhances the already existing features of the existing design or creating some wholly new features that will complement the original design. These cups are a good example of that, some others might be those cup holder things in Starbucks that allow you to pick up your hot cup.