Answer:
OB. Made out of straw.
Step-by-step explanation:
An adjectival phrase is a group of words or phrases that describes or modifies a noun or a pronoun in the given sentence. They can also act as adjectives and are placed before or after the noun in the sentence.
In the given sentence, the nouns are "wolf", and "house". And looking at the sentence structure, the adjectival phrase that modifies or explains a noun is "made out of straw". This phrase describes the noun "house", while at the same time, the sentence can also be complete without this phrase.
Thus, the correct answer is option B.