What area of the brain is most closely correlated with production of speech?

An individual comes into a clinic after a minor stroke. His family states that since his stroke he has begun to speak in nonsense. His word choice seems random, with nouns and verbs that are unrelated, and bizarre syntax and grammar. He also does not seem to be able to understand when he is addressed directly. His affect has not changed, nor has his basic motor coordination.

He likely suffered injury to which of the following areas of the brain?