Many cell phone companies have similar offers and restrictions for changing numbers, adding numbers to a plan, getting a new phone, paying for minutes used beyond the allotted minutes, and so on. these similarities are due to which of the following processes?

Based on the scenarios, it will be very likely that the similarities are due to institutional isomorphism
In business, institutional isomorphism refer to a similarity of processes or structure of one organizations with the other because they've developed under the same constraints

hope this helps