Teagan is exploring options to invest in real estate. She collects information from several sources: 1. a real estate investment book written by a well-known author 2. a news article about the latest real estate market trends 3. the annual report of a real estate investment trust she is interested in 4. a real estate investing online forum where users share their success and failure stories To make a well-informed investment decision, which source should Teagan trust the most?