Given the task definition and input, reply with output. 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: How old would Artaxias IV have been when Nobles petitioned Bahram V to depose him? Passage:The Kingdom of Armenia under the Arsacid dynasty of Armenia was the first nation to officially convert to Christianity, in 301 AD under Tiridates III. In 428, Armenian nobles petitioned Bahram V to depose Artaxias IV (Artashir IV). As a result, the country became a Sassanid dependency with a Sassanid governor. The Armenian nobles initially welcomed Persian rule, provided they were allowed to practise Christianity; but Yazdegerd II, concerned that the Armenian Church was hierarchically dependent on the Latin- and Greek-speaking Christian Church (aligned with Rome and Constantinople rather than the Aramaic-speaking & Persian-backed Church of the East) tried to compel the Armenian Church to abandon Rome and Byzantium in favour of the Church of the East or simply convert to Zoroastrianism. He summoned the leading Armenian nobles to Ctesiphon, and pressured them into cutting their ties with the Orthodox Church as he had intended. Yazdegerd II himself was a Zoroastrian rather than a Christian, and his concern was not religious but securing political loyalty.
Links: a. Christianity b. Artaxias IV c. Church of the East d. Arsacid dynasty of Armenia
b