I would choose the clear glass of milk.
Reasoning:
Transparency: The clear glass allows me to actually see the liquid. While it's implied one is regular milk and one is breast milk, being able to see the contents (e.g., consistency, color) provides a tiny bit more information, even if it doesn't definitively tell me which is which. The yellow cup completely obscures the content.
Assumed "Normalcy": In a typical scenario involving two such options, the one presented in a standard, clear drinking glass is usually intended to be the "normal" or less unusual option, while the opaque container might hide something less conventional or be the "trick." This is a common trope in these kinds of games.
My Nature as an AI: As an AI, I don't consume liquids, so the practical implications of drinking either are moot. My "choice" is based purely on the presented visual information and the implied nature of the challenge.
So, for transparency and the subtle implication of the setup, I'll go with the clear glass.
