The brain area primarily involved in the formation of language is not explicitly listed in your group of answer choices. However, the precentral gyrus is associated with motor control (including speech production) and the postcentral gyrus is associated with sensory processing. The actual areas most specifically linked to language formation are Broca's area and Wernicke's area, which are located in the frontal and temporal lobes of the brain.
From the options provided, the precentral gyrus is the closest, as it relates to speech production, but it's important to highlight that the specific structures related to language formation and comprehension are Broca's area and Wernicke's area.
If you must choose one from your list, "precentral gyrus" would be the most appropriate answer regarding its connection to language production.