Which of the following medication acts as an antagonist on mu receptors and agonists of kappa receptors?

A. Morphine is a full agonist on mu receptors and does not act on kappa receptors in the same way. B. Naloxone is an opioid antagonist that blocks both mu and kappa receptors. C. Butorphanol is a mixed opioid agonist-antagonist that acts as an agonist on kappa receptors and an antagonist on mu receptors. It is used for pain management and has a lower risk of dependence compared to full opioid agonists. D. Acetaminophen does not act on opioid receptors and is not classified as an opioid.