Kind of a special question today :)
I just had a test at my technical university where I was told that I am wrong.
So I like to know from you folks(I believe
You're wrong... for the class. In class, what teacher/book says goes.
Outside class, I agree with you 100%.
I would think MVC does go deeper than presentation tier for the simple reason that supplying the model does require other tiers to do "something".
Besides if we think of model as some representation of Domain concepts (see DDD) - then we are already talking about going outside of Presentation tier.
Your teacher is right, the "model" merely represents data that is to be presented. For example, the data that makes up a web page.
The data itself will ultimately come from the business layer, but the model should be restricted to the presentation layer. It's the model of your presentation.
For example, you might retrieve data as datasets, and use the datasets to build page-specific models.