Answer: The right answer is the B) The art of storytelling.
Explanation: Just to elaborate a little on the answer, it can be added that a noun phrase must, by definition, be formed at least by a noun (plus its modifiers, if it is accompanied by any). None of the other phrases include a noun, but verbs and a conjunction (as soon as). "The art of storytelling" functions as the object of the verb "has been interested." It is formed by a noun, "the art," and a postmodifier, "of storytelling," which is a prepositional phrase.