Neurocognitive Linguistics is an attempt to understand the linguistic system of the human brain. The object of investigation is the mental system that supports our language processing __________. That is the basic challenge facing neurocognitive linguistics. But since our linguistic systems are housed in our brains, we have no choice but to treat language as a mental phenomenon
Answer: B
The second sentence introduces the mental system associated with our language system. Therefore it is right to discuss about its mechanism and uniqueness.