Answer: b. On the tip of tongue.
Explanation:
The taste buds are present on the sensary organ that is tongue. On tongue taste receptor cells or taste buds in the form of papillae are present which detect different tastes. These receptors can detect taste stimuli like salty, sweet, bitter, sour and umami. Sweet is detected by the receptor cells or taste buds in the front of tongue. Sour and salty on the sides and in the back bitter taste can be detected.