Answer: A. To show that it is an activity with some history
Explanation:
You attached no article or a reference to one but the above should be correct.
When introducing a topic such as a sports activity, it is best to talk about the history of that activity so that the reader can understand how the sport has started and how far it has gone since then.
In this case therefore, assuming the article is about mountain climbers, it would be best to talk about the earlier mountain climbers to show that mountain climbing is not a new thing as it has history and has come a long way. It can also motivate prospective mountain climbers.
