Identify the choice that uses one or more transitions to correctly indicate a causal relationship. a. after he drove from la to san francisco to see his girlfriend; therefore, drove right back to la. b. he drove from la to san francisco to see his girlfriend, so he drove right back to la. c. after he drove from la to san francisco to see his girlfriend, he drove right back to la. d. he drove from la to san francisco to see his girlfriend, which energized him to drive right back to la.