Some of the items on my shopping list, chanterelle mushrooms, white asparagus, and eel, were impossible to find.
Explanation:
Commas in this case, generally your going to add commas in a place where you would take a breath. This wouldn't be colons because thats more of an indication of a place that you could also fit comma-and. Parenthesis clearly don't fit. The only other risk is dashes because you could in theory do "Some of the items on my shopping list-chanterelle mushrooms, white asparagus, and eel-were impossible to find. " But that doesn't read as smoothly so its the less safe of the two choices
In Jack London's "To build a fire" the main theme is Man vs. Nature, the main character is crossing the Alaskan frozen landscape, following the path of the Yukon river. He dismisses the advice of the old-timer and he also doesn't pay attention to his companion, the dog who can feel the threat of the harsh weather. The right answer is the second option.