The sentence that uses a transition to correctly indicate a causal relationship is B. I could not wait to tell them what I had seen; as a result, the words just spilled out of my mouth.
In the sentence, the transition word used is "as a result" which clarifies the cause-consequence relationship. As the person could not wait to tell people what he or she had seen, his or her words just spilled out of his ir her mouth.
In options A and C, there isn't a cause-consequence relationship between the actions. In option D, however, there is a cause-consequence relationship between the ideas. As the person was feeling sad, he or she decided to go to the mall. But there is no transition word used in the sentence to indicate such a relationship.
