You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
American_Idol

Context:
The thirteenth season premiered on January 15, 2014, with Ryan Seacrest returning as host. Randy Jackson and Keith Urban returned, though Jackson moved from the judging panel to the role of in-mentor. Mariah Carey and Nicki Minaj left the panel after one season. Former judge Jennifer Lopez and former mentor Harry Connick, Jr. joined Urban on the panel. Also, Nigel Lythgoe and Ken Warwick were replaced as executive producers by Per Blankens, Jesse Ignjatovic and Evan Pragger. Bill DeRonde replaced Warwick as a director of the audition episodes, while Louis J. Horvitz replaced Gregg Gelfand as a director of the show.

Question:
Who directed the thirteenth season of American Idol?

Gregg Gelfand