For which of the following is demand likely to be the most price inelastic?

That or furniture, both are necessities in my opinion. There is public tranportation so there is a possible substitute, no real substitute for furniture. Hotel rooms and airline travel are part of doing business with no equal substitute. If your teacher marks you off use my arguments to defend your answer, even if they don't change it they will see your reasoning and will probably be at the least impressed with your understanding of the material. My econ teacher has struck quite a few questions from her exams for reasons such as this.