There are two things that you can touch upon as an answer to this question. The first relates to the statistics regarding the sector. Tell your interviewers that it is a dynamic sector that is growing at a rapid pace and you want to be in the middle of the boom, the excitement and the energy. However, before saying so, make sure that you have the required data to support your claims. What is the growth rate of the industry? What is the size of the industry? When did the boom start? Who says there is a boom? Basically, doing your homework well is advised in case you want to wax eloquent on the hotel and tourism industry.
The other aspect that you should always touch upon as an answer to this question is how you and your personality are well suited to this sector. Convince the interviewers that you are made for the industry and the industry is made for you. Talking about basic traits like people skills, patience, ability to work under pressure criteria, which are prerequisites to succeeding in the hospitality and tourism sector and how you excel at all these, should constitute a good answer
Knowing your text books well always helps, especially when you are faced with questions like these. Talk about the different sectors like house keeping, accounting, maintenance, public relations, security, sales, food and beverages, front office and accounting and give brief descriptions if asked. Say something about how each one is important for the proper functioning of a hotel.
Any hotel or tourism institute worth its salt spends a lot of time teaching its students about dealing with tough customers. Checking your textbooks for answers is a good idea, but please manages to do so before the interview takes place. If you know somebody in the industry, then it would be a good idea to speak to him or her and ask about how such situations are handled real time, in the real world. If you can base your answer on these inputs, then nothing to beat it. If you have time, then give an example or two about how you dealt with an angry or bad customer in the past with tact, politeness and firmness.
This seems like a simple enough question, but it is more like a trick question. Many interviewees, either due to anxiety, or because of the overconfidence that comes from being asked such a simple question, mess this up by missing out an important step of the process. Think this out carefully, remember everything that you have been taught or have done and then answer this question slowly and methodically, convincing your interviewers that you can handle a situation under pressure well.