A cell phone is a piece of hardware. To utilize the phone to make a call, you require signing up for cell phone service. Outside of the US it is common for people to buy a cell phone from any company they choose and then sign up for cell phone service with any company they choose, even a different one. In the US, most of the time phones are locked, meaning people should sign up for service with the same company that they buy the phone from. This practice in the US is an example of

Select one:

1. Price discrimination

2. Monopolistic competition

3. Government franchise

4. Bundled products

5. Legal harassment