Sentence: “ Unfortunately , people are trading on the fact these harnesses and vests have become distinguishing marks of service dogs , so now you find unscrupulous businesses who sell these things to people who want to take their dogs into the store or restaurant or in the passenger cabin of the plane , ” said Paul Mundell , national director of canine programs for CCI .
Span: businesses who sell these things
Question: How many businesses are selling harnesses and vests for service dogs?