Sentence 1: Larson had bought a new house. 
 Sentence 3: Larson met with a real estate agent 
 Sentence 4:  They agreed on a price to sell the house 
 Sentence 5:  Larson and the real estate agent eventually sold the house 
 Option 1: He is giving his old house to his sister. 
 Option 2: He was putting his old house up for sale.