Final answer:
The phrase 'permitted close to the launch pad' in the sentence functions as an adverb phrase, as it modifies the verb by indicating where the action of being permitted is not occurring. Therefore, the correct identification of the phrase in bold is an 'adverb phrase'.
Step-by-step explanation:
The sentence in question is 'No unauthorized personnel were permitted close to the launch pad'. To identify the phrase in bold, which is 'permitted close to the launch pad', we need to understand what function it serves in the sentence.
An adjective phrase modifies a noun, an infinitive phrase usually begins with 'to' followed by a verb, an appositive phrase renames or clarifies a noun, and an adverb phrase modifies a verb, an adjective, or another adverb by answering questions like how, when, where, why, to what extent, or under what conditions.
In this case, 'permitted close to the launch pad' is describing where the 'unauthorized personnel' were not allowed to be. The phrase answers the question 'where were the unauthorized personnel not allowed to be?' which suggests it is modifying the verb 'were permitted', indicating where the action is not happening. Therefore, it is an adverb phrase.
The correct option in the final answer is adverb phrase.