Answer: C. have been waiting patiently for winter since the spring.
Explanation: A verbal phrase is the part of a sentence that contains the verb and any direct or indirect objects, but it doesn't include the subject (the person, animal or group that perform the action of the verb). In the given sentence, the subject is "I" and the verbal phrase is " have been waiting patiently for winter since the spring", where the verb is "have been waiting" and the rest of the phrase are the modifiers.