4.In 1939, Lena leased a building to Mary that was to be used "solely as a filling station and not for restaurant or lunch counter purposes" for a five- year period at a rental of $100 per month. After three years, Mary offered to restore possession of the property to Lena. Mary claimed that World War II government regulations that froze the sale of automobiles and rationed the sale of gasoline made it impossible for her to use the leased property as a filling station. Lena refused to ter- minate the lease and claimed that Mary must pay rent for a full five-year term. Is Lena correct? Why or why not?