The correct answer is option four:
Dinner is almost ready, so please put your phone away before eating.
An adverb phrase consists of one or more words which act as an adverb, so it can modify a verb, adjective or another adverb. It indicates how, when, where or why something happens. In sentence four, the adverb phrase is "before eating."
In sentence one, the expression "and don't look at it again" is a coordinating clause. Sentence two contains an adverb clause: " before I have to ask you again." Finally, alternative three also possesses a coordinating clause: "and let it charge overnight."
