Read the following excerpt from an intercalary chapter from a novel about a group of modern-day mountain climbers struggling to achieve a goal despite personal differences:

when ernest shackleton led his party toward the south pole in 1909, they could have made it. they had enough food and fuel. they could have been first. but they wouldn't have made it back. and he knew it, so he let go of that dream and focused instead on getting his men home alive. by including this intercalary chapter, what effect is the author most likely attempting to achieve?
a. the author wants to provide commentary, separate from the narrative, that illustrates an individual experience with mountain climbing.

b. the author wants to carry the theme of perseverance beyond the scope of the narrative by illustrating it to readers in a separate setting.

c. the author wants to break from the narrative flow of the mountain climbers' story to provide relevant background information.

d. the author wants to give readers a better understanding of the history of exploration and the events that led to present circumstances.