You will be given a definition of a task first, then some input of the task.
This task is about writing a correct answer for the reading comprehension task. Based on the information provided in a given passage, you should identify the shortest continuous text span from the passage that serves as an answer to the given question. Avoid answers that are incorrect or provides incomplete justification for the question.

Passage: In 2015 Beyonce signed an open letter which the ONE Campaign had been collecting signatures for; the letter was addressed to Angela Merkel and Nkosazana Dlamini-Zuma, urging them to focus on women as they serve as the head of the G7 in Germany and the AU in South Africa respectively, which will start to set the priorities in development funding before a main UN summit in September 2015 that will establish new development goals for the generation. Question: Beyonce signed a letter with who in 2015?
Output:
the ONE Campaign