**Core Concept**
The concept being tested is pharmacological antagonism, where two drugs interact with different receptors to produce opposite effects. This is a fundamental principle in pharmacology, where understanding the mechanisms of action and interactions between drugs is crucial for effective treatment and prevention of adverse reactions.

**Why the Correct Answer is Right**
One classic example of two drugs with opposite actions on different receptors is adrenergic agonists and antagonists. Adrenergic agonists, such as epinephrine, stimulate alpha and beta-adrenergic receptors, causing vasoconstriction and increased heart rate. On the other hand, adrenergic antagonists, such as propranolol, block beta-adrenergic receptors, preventing the increase in heart rate and blood pressure caused by epinephrine. This is a classic example of pharmacological antagonism, where two drugs interact with different receptors to produce opposite effects.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not specify the mechanism of action or the receptors involved, making it a vague and non-specific answer.
* **Option B:** This option is incorrect because it does not provide a clear example of two drugs with opposite actions on different receptors, and is therefore a distractor.
* **Option C:** This option is incorrect because it refers to a different concept, where a drug has both agonist and antagonist effects on the same receptor, which is not the correct answer.

**Clinical Pearl / High-Yield Fact**
When prescribing drugs, it is essential to consider the potential for pharmacological antagonism, where two drugs interact with different receptors to produce opposite effects. This can lead to either additive or synergistic effects, or even adverse reactions.

**Correct Answer:** C.