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.
Q: Question: When the first war between the supporters of Maria Christina and Carlos of Borbon begin? Passage:The Basque Country was one of the main sites of battles during the First Carlist War, a civil war between supporters of the Spanish regent Maria Christina, known as liberals, and those of the late king's brother Carlos of Borbon, known as Carlists. The Carlists were particularly focused on capturing Bilbao, a liberal and economic bastion in northern Spain. The Carlist general Tomas de Zumalacarregui tried to take the city during the Siege of Bilbao of 1835, but he was wounded during a battle near Begona and died some time after in the town of Zegama. The next year, the city resisted a second siege during which the liberal general Baldomero Espartero defeated the Carlists in the Battle of Luchana. The city was untouched by the Second Carlist War, which took place mostly in Catalonia, but was again an important scenario during the Third Carlist War; in April 1874 the city suffered a third siege which lasted two months.
Links: a. First Carlist War b. Catalonia c. Baldomero Espartero d. First Carlist War
A:
a