51.
Your Answer is
Correct Answer is B
Explanation
According to the sentence meaning "A fine speaker, Lease presents complex events, such as interest rates, in a confident and direct manner that is easily understood by the audience". Therefore judge, in a confident, straightforward manner to modify complex issues. Therefore, such as interest rates are separated by double commas. Confident and straightforward are adjectives of the same level to modify the noun manner, with a comma in between.