**Core Concept**
The bitter taste sensation is mediated by specific receptors on the tongue, which play a crucial role in protecting against toxic substances. These receptors belong to the family of G protein-coupled receptors (GPCRs) and are activated by various bitter compounds found in food and drinks.

**Why the Correct Answer is Right**
The bitter taste sensation is primarily carried by T2R receptors, also known as bitter taste receptors. These receptors are expressed on the apical surface of taste bud cells in the tongue and are activated by a wide range of bitter compounds, including those found in plants and some medications. When activated, the T2R receptors trigger a signaling cascade that ultimately leads to the transmission of the bitter taste sensation to the brain.

**Why Each Wrong Option is Incorrect**

* **Option A:** This option is incorrect because it does not specify the type of receptors responsible for bitter taste. While T1R receptors are involved in sweet and umami taste, they are not responsible for bitter taste.
* **Option B:** This option is incorrect because it does not accurately describe the location of bitter taste receptors. Bitter taste receptors are found on the apical surface of taste bud cells, not on the basolateral surface.
* **Option C:** This option is incorrect because it does not specify the type of receptors responsible for bitter taste. While some GPCRs are involved in bitter taste, the specific type of receptor responsible for bitter taste is T2R.

**Clinical Pearl / High-Yield Fact**
It's worth noting that the bitter taste sensation is an important mechanism for protecting against ingesting toxic substances. In fact, many plants have evolved to produce bitter compounds as a defense mechanism to deter herbivores.

**Correct Answer:** C. Taste buds on the tongue.