Answer:lips
Explanation: The sensory homunculus is a mapping that is done and it allows the location of various somatosensory receptors in the body mapped onto a somatosensory cortex.
This maps helps to view the sensitive part of the body such as the lower face, lips. The projection of this sensitive body part is based on the number of corticles it has. more receptors are linked to cortex with large mapping area.
The lips response to stimulus due the large number of receptor it has and it has the largest region of somatosensory cortex