You will be given a definition of a task first, then some input of the task.
In this task, you're given a question, a context passage, and four options which are terms from the passage. After reading a passage, you will get a brief understanding of the terms. Your job is to determine by searching and reading further information of which term you can answer the question. Indicate your choice as 'a', 'b', 'c', or 'd'. If you think more than one option is plausible, choose the more probable option to help you answer the question.

Question: Which of Haywood's compatriots who made broadcast from Madrid is the oldest? Passage:Haywood's military career included service in three wars. His interest in military combat began when his friends recalled tales of their service in the Eighth Illinois, Black National Guard Regiment. During World War I, he served with the Eighth Regiment, a black United States regiment. In the Spanish Civil War, like many Americans there, he fought for the Popular Front with the Abraham Lincoln Battalion of the International Brigades. Haywood held the position of Regimental Commissar in the XV International Brigade during the Battle of Brunete. While in Spain he, Langston Hughes and Walter Benjamin Garland broadcast from Madrid in support of the Republican cause. During World War II, he served in the Merchant Marine, where he was active with National Maritime Union.
 Links: a. Langston Hughes b. Popular Front (Spain) c. Langston Hughes d. Langston Hughes
Output:
a