I'm not a determinist so i am not willing to acknowledge that I cannot make my own decision about these things rationally, without reference to the goal of my own choosing. And I would think since I can choose "none of the above," including death, then that's evidence that I can rationally choose my telos.
Telos is not for you to choose Cassius . It's the ultimate goal for living creatures set by Nature. Telos for living creatures is pleasure. Human rationality can change it as much as I can rationally decide I can jump 10 feet high. I can't. It doesn't mean Nature took free will from me. Free will is not an ability to do whatever one wants. It's the ability to do whatever is permitted within a framework called Nature. Humans are part of Nature. We are not above it. We cannot set our own telos. That would make us supernatural. It would render philosophy completely meaningless too. Philosophy is not a discipline that can teach us how to jump 10 feet high. It's a discipline that teaches us how high we can actually jump. I think Don and Todd explained this clearly enough.