As for this problem concerning about a transition between sentences and paragraphs, the most probable and most likely to be the answer out of the options presented would be the third one which is a bridge.
A transition serves as a bridge between sentences and paragraphs. Though they create a divide between them, these transitions do not necessarily indicate that the divide is to cause to present that the two aren't connected to each other. A summary and introduction wouldn't do since a transition functions more and effectively between sentences and paragraphs.
Lucy discover Narnia first and meets Mr. Tumnus. Mr. Tumnus is interested in Lucy because he is lonely and needs a friend
Answer: I am delighted to introduce Dr. Anna Smith, a psychiatrist, who will talk to us about parent-child relationships.
Explanation: There should’ve been a comma after psychiatrist.
