Question

Which part of the sentence is a participial phrase?
The cookies, baked this morning, were all gone by five o'clock.
A) the cookies
B) by five o’clock
C) were all gone
D) baked this morning

Answer 1

I think is D and

hope this helps you friend

Answer 2

Option (D) baked this morning is the correct answer to the question.

Participial Phrase

A Participial Phrase may be defined as a group of words that consists of a participle (present or past), complements, objects, and modifiers. By, modifying a noun or pronoun, it performs the function of an adjective, also.  

As per the above-given description option (D) becomes the most appropriate choice as it fulfills the described criterion.