This is just underhand. The hints say that trở thành means ‘become, be, get’. ‘I want to be(come) a computer’ obviously doesn't make sense, so the meaning must be ‘I want to get a computer’. Trouble is, there are no tiles for ‘to get’, and then the most reasonable thing is to try ‘I want a computer’, which conveys the same meaning. But it turns out to be wrong.