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: Who were the leaders Domhnall Ua Buachalla followed during the Easter Rising? Passage:He was a member of the Irish Volunteers and on the outbreak of the 1916 Easter Rising he walked the 26 kilometres to Dublin to fight in the Rising. He was imprisoned in the mass arrests and deportations that followed, and released in 1917. Like many Rising survivors, he joined Sinn Fein, a small separatist party that was wrongly blamed by the British government for the Easter Rising. In the aftermath of the Rising, survivors led by Eamon de Valera took over the party in the struggle for the establishment of an Irish republic. Ua Buachalla was elected as a Sinn Fein MP for Kildare North at the 1918 general election. He served in the First Dail (19181921), and was re-elected to the Second Dail in 1921 as a Teachta Dala (TD) for KildareWicklow. He sided with de Valera and opposed the Anglo-Irish Treaty. He fought in the Four Courts in the Civil War. Imprisoned in Dundalk jail, he was released by the Anti-Treaty troops in August 1922. He lost his seat at the 1922 general election, and was an unsuccessful candidate at the 1923 general election.
Links: a. Irish Volunteers b. Irish Volunteers c. 1922 Irish general election d. KildareWicklow (Dail constituency)
Output:
a