Final answer:
Area 3a is responsible for proprioception, being a part of the primary somatosensory cortex in the postcentral gyrus where it receives and processes information about the body's positioning.
Step-by-step explanation:
Out of all sections of the primary somatic sensory cortex, the area specifically responsible for proprioception is Area 3a. Brodmann's Area 3a is located in the postcentral gyrus of the parietal lobe, alongside Areas 1, 2, and 3b, which collectively compose the primary somatosensory cortex. Area 3a is where conscious perception of the body's positioning is received from the thalamus. Area 3a, along with these other regions, processes tactile senses such as touch, pressure, and vibration. However, it is distinctive for its role in processing proprioceptive information, which is essential for understanding the position, motion, and equilibrium of our bodies.