Which of the following sentences is punctuated correctly?
AWe went to the zoo; therefore, I am an expert on penguins.
BWe went to the zoo; therefore I am an expert on penguins.
CWe went to the zoo, therefore, I am an expert on penguins.
AWe went to the zoo; therefore, I am an expert on penguins.
BWe went to the zoo; therefore I am an expert on penguins.
CWe went to the zoo, therefore, I am an expert on penguins.