For the Past 20 Years, Perry Has Been an Owner

For the past 20 years, Perry has been an owner of several Coldwell Banker Real Estate franchises.To increase business Perry spends a great deal of money marketing and advertising his businesses online.Perry decides he would like to move beyond just marketing and create an actual ebusiness that acts like a search engine but only focuses on the real estate industry.The main revenue source for this Perry's ebusiness will be a charge of $50 a month for each property that is listed on the website.What is the primary revenue model for Perry's new business?

A) license fees
B) advertising fees
C) subscription fees
D) All of these are correct.