Theme in The Call of the Wild.

The Call of the Wild is a story of transformation in which the old Buck—the civilized, moral Buck—must adjust to the harsher realities of life in the frosty North, where survival is the only imperative.

That's the theme of the Story,Book,Movie

Thanks Diamonds is the name, ^-^

answer: b) bubbling its way

explanation: an adjective is a word or a group of words that modifies a noun (name, thing, place,

in this case, the first option "to heartily enjoy" isn't describing or modifying any noun, the third option "hiking along merrily" is describing an action but it doesn't modify any noun, the last option "beside us" is just a preposition that indicates position, so the correct answer is the second one: "bubbling its way" because it is modifying the noun "stream".