Answer:
Option 2, transduction occurring from the taste buds
Step-by-step explanation:
The taste buds on the tongue have specific taste receivers which are able to send sensation to the brain thereby allowing it to perceive the taste.
There are specific chemical stimulation that represents a certain taste for example -
Sweet taste is represented by sugars
Salty taste is represented by sodium chloride and other salts
Umami taste is represented by amino acid
Sour taste is represented by acid
Bitter taste is represented by alkaloids
These chemical simulator stimulates the sensory neuron through which brain perceives the taste.
Hence, option 2 is correct.