Choose the word modified by the underlined participle or participle phrase the -wailing- baby scared the skittish puppy 1.)baby 2.)scared 3.)skittish puppy

The word modified by the underlined participle or participle phrase is baby

Explanation:

Participles can have to ending forms, -ed or -ing, the participle in this sentence is wailing which can function as an adjective, adjectives modify, describe or affect nouns, then the noun that is described by the word wailing is baby, the sentence says that the baby was crying a lot with a prolonged high pitch sound.