Question

the purple area of the tongue presented above are the taste buds for:
○ sweet
○ bitter
○ sour
○ salty

Explanation:

The purple (or pinkish - purple as per the image) area in the middle of the tongue is associated with the taste buds for sweet. The taste map of the tongue indicates that the center (or the purple - like area here) is responsible for detecting sweet tastes. Bitter is detected at the back, sour at the sides, and salty also at the front - sides, so the purple area here corresponds to sweet.

Answer:

sweet (the option with "sweet" text)