Final answer:
The primary projection area for somatosensory information, the primary somatosensory cortex, is located in the parietal lobe (option b) of the brain. It processes various tactile senses and is responsible for somatosensation like touch, temperature, pain, proprioception, and kinesthesia.
Step-by-step explanation:
The location of the primary projection area (S1) for somatosensory information, known as the primary somatosensory cortex, is in the parietal lobe of the brain. This area processes sensory information from across the body, including touch, temperature, and pain. The somatosensory cortex has a specialized structure where different parts of the cortex are dedicated to processing sensations from corresponding different parts of the body. Each region's size in the somatosensory cortex is determined by the sensitivity and the number of nerves of the body part it represents.
The parietal lobe is located immediately behind the frontal lobe and is primarily responsible for integrating sensory information. It contains the postcentral gyrus, which is identified as Brodmann's areas 1, 2, and 3. Here, a multitude of tactile senses such as touch, pressure, pain, and temperature are processed. This lobe also is involved in proprioception and kinesthesia, which are the senses of body position and movement.
While the parietal lobe is responsible for somatosensation, other lobes of the brain carry out different sensory functions: The occipital lobe begins visual processing, the temporal lobe contains areas for auditory processing and memory formation, and the frontal lobe is mainly associated with motor function and higher cognitive skills. The correct option for the location of the primary somatosensory cortex, considering all the information presented, is the parietal lobe (option b).