D. Dad
In this sentence, dad is being used as a name or proper noun. It needs to be capitalized.
The correct answer is B. She places the theme at the end of her speech, where it will be most memorable to the audience. Sonia Maria Sotomayor is an Associate Justice of the Supreme Court of the United States, appointed by President Barack Obama in May 2009. She has the merit of being the first justice of Hispanic descent and the first Latina. In order to make her speech unforgettable, she uses the theme at the end of it.
