If you ask me about the person who has the most A. Hard word

Choose the word (A, B, C or D) that best fits the blank space in the following passage

If you ask me about the person who has the most influence on my life, I must (13)________ you it is my father. You ask me what I think about my father. Great! great! My father is the best person in the world. Do you know what I (14)_____ ? He is a considerate and generous man who is loved not only by his family (15)______ by all his friends. His great sense of humor (16)_______ him from others. To his colleagues, he is a (17)_____ man who is always helpful and creative in his job. In a word, my father’s terrific! I’m so happy to have him as a friend, an advisor, and (18)_____ a father. I love him so much. Happy Father’s Day, Daddy!