Question ID:PT80 S3 Q22 Passage:Three real estate companies‚ RealProp, Southco, and Trustcorp‚ are considering trading buildings with one another. Each building they own is categorized as either class 1, class 2, or class 3, depending on its approximate value:RealProp owns the Garza Tower (class 1), the Yates House (class 3), and the Zimmer House (class 3). Southco owns the Flores Tower (class 1) and the Lynch Building (class 2). Trustcorp owns the King Building, the Meyer Building, and the Ortiz Building, all of which are class 2.Each trade must be of exactly one of the following three kinds:Trading one building for one other building of the same classTrading one class 1 building for two class 2 buildingsTrading one class 2 building for two class 3 buildings Stem:If Trustcorp owns no class 2 buildings after some number of trades, which one of the following must be true? Correct Answer Choice:EChoice A:RealProp owns a class 1 building. Choice B:Southco owns only class 2 buildings. Choice C:Southco has made at least one trade with Trustcorp. Choice D:Trustcorp owns the Garza Tower. Choice E:Trustcorp owns the Zimmer House.