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 was King George III when his seventh son was born? Passage:In 1793 George Vancouver named Point Adolphus (at the northern tip of Chichagof Island, and today a well-known humpback whale feeding area) after Adolphus Frederick, seventh son of King George III. In 1878, W.H. Dall, while working on a coastal survey, saw "Adolphus" on the map and assumed it was for Swedish king Gustavus Adolphus. The point across Icy Strait from Point Adolphus at the mouth of Glacier Bay was not named on the map, so Dall called it "Gustavus". Another possibility is that Dall named Gustavus for Gustavus C. Hanus, a U.S. Naval Academy graduate who had extensive experience throughout southeast Alaska, and both Dall and Hanus served with the Coast Survey in Alaska. Hanus laid out the first streets in Juneau and helped quell the trouble in Klukwan in 1881.
Links: a. Juneau, Alaska b. Prince Adolphus, Duke of Cambridge c. Gustavus Adolphus of Sweden d. Klukwan, Alaska
b