Mr. B rents a house owned by Mr. A with an area of ​​70m2, from 7/7/2020 (including a 30m2 house and a 40m2 front garden) for one year (B has a deposit of 1 month rent, and the house rent was notarized). With the consent of A, on August 17, 2020, B self-repaired the house to be more spacious with his own money about 3 million dong. After 2 months, on September 10, 2020, Mr. A informed Mr. B that she would sell the house to Miss. C. Even when Miss C become a new owner, she informs Mr. B that she would use the area in front of the house for building a motel with the size of about 30m2. The rest of the area is the entrance to Mr. B's house, and simultaneously Mrs. C will increase the rental price. Mr. B is angry because the duration of house rent is still up to 10 months, Ms. C does not have the right to break the agreement despite the owner's change. Reducing the size of house rent and increasing rental payment are unreasonable and illegal. However, Miss. C disagrees the claim of Mr. B