Alexis is MLO and friend of real estate agent Shannon. Alexis finds out Shannon is hosting an open house for one of the properties she is selling and brings some flyers by for Shannon to distribute at the open house. The flyers contain marketing information about Shannon's real estate business and Alexis' mortgage lending services. Alexis offers to provide flyers for all of Shannon's open houses if Shannon will refer potential customers to her for prequalification. Shannon declines to distribute the flyers and explains to do so would be a violation of what law?