Answer:
3. Complexity
Step-by-step explanation:
Complexity is a characteristic that has an inverse relationship with an innovation's rate of adoption. This is because the more complex an innovation is, the harder it is for the majority of people to become well-acquainted with it.
For example, until the early 1990s, personal computers were very hard to use because they required at least rudimentary knowledge of programming. Most people did not know how to program then (most people do not know how to program in the current year), and this lack of skills prevented them from adopting a highly innovative product such as personal computer.