Ethnic cleansing in Grade 4?

A class in a school in New Brunswick has made the news because one grade 4 student was upset about a recent exercise the teacher assigned (see story here). The students were asked a question based on the following scenario: Imagine an Acadian francophone on a planet with an anglophone, a black African, a Chinese person, and an Aboriginal person. The planet is going to explode and you can only fit 3 people in the rocket. You have 10 minutes to decide. Which three should be saved? Are you kidding me? Why is it a grade 4 student (who is adopted from Ethiopia, and from the interview I heard on the radio yesterday, one of the only children of colour in the school) the only one to see the problem with this exercise. The teacher saw nothing wrong with it. The principal, during an interview, said there was nothing wrong with the exercise. Some of the conversations created between the students were great. Some students said the francophone, anglophone, and aboriginal should be saved, because they can communicate. some said the same group should be saved because they were the first ones here (who is teaching history in this school and whose history are they teaching?) This exercise is wrong on so many levels. With so little information given to the students, their decisions had to be made on stereotypes and outward appearance. This sounds like a training exercise for genocide 101. How can anyone justify and defend this exercise. Remember the most dangerous people are those who think they know what they don't know