How Do Citrus Fruits Such as Lemons Cause the Basic

How do citrus fruits such as lemons cause the basic taste of sour?

A) Citrus fruits release protons (from citric acid) that flow directly into taste cells through H⁺ channels in the plasma membrane.
B) The vitamin C of citrus fruits binds to specialized receptors on the plasma membrane of taste cells that trigger a sour taste response.
C) Sugars and vitamin C molecules bind simultaneously to receptors on the taste cells,creating a mix of bitter and sweet that results in the sour taste.
D) Citric acid amplifies the sour taste of vitamin C when it binds to specialized receptors on the taste cells.