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: What year was the man who went around the world on the HMS Beagle born? Passage:Beagle is a crater lying within the Margaritifer Sinus quadrangle (MC-19) portion of the planet Mars, the crater is one of multiple topographical depressions within the Meridiani Planum extraterrestrial plain, which was explored by the Opportunity rover. It was located by the rover in images taken on sol 855 (June 20, 2006), 310 metres (1,107ft) away. It is on the edge of the much larger ejecta blanket surrounding the crater Victoria, named the Victoria Annulus. This impact crater was named in honor of HMS Beagle of the Royal Navy, ordered in February 1817, which carried Charles Darwin on his voyage round the world.
Links: a. Charles Darwin b. Opportunity (rover) c. HMS Beagle d. Opportunity (rover)
Output:
a