Question: The Spokane and Inland Empire Railroad Company later merged into a United States-based company formed from a merger of four what?
Sentence (from "San Bernardino, California"): As one of the Inland Empire's anchor cities, San Bernardino spans 81 sqmi on the floor of the San Bernardino Valley and has a population of 209,924 as of the 2010 census.
Relevant evidence: No