Answer:
A. Voltage-gated Ca² channels open, triggering the release of neurotransmitters.
Explanation:
For taste mechanisms to function properly, it is necessary the activation of taste receptors.
Through the activation of taste receptors, transduction cascades occur, involving ion channels that are located in the apical or lateral membranes. There occurs a subsequent release of chemical neurotransmitters that send signals to the control centers.
Salty and sweet flavors produce the membrane depolarization that results in Ca+ ions´ entrance to the cell. Ca+ initiates the release of neurotransmitters. Afferent gustative neurons receive the message and send it to the control center, the encephalon. After that, gustative cells go back to the initial state, repolarizing.