Final answer:
The correctly punctuated sentence is "Reagan, Karina, and I watch the amazing sight above us," properly using commas to separate the list of subjects.
Step-by-step explanation:
To answer the question, the sentence with the correct punctuation is: "Reagan, Karina, and I watch the amazing sight above us." This sentence has a subject which is the group consisting of Reagan, Karina, and the speaker (I), and a verb 'watch,' which describes the action they are doing.
Together, they observe something extraordinary happening above them. It's important to punctuate this sentence correctly by using commas to separate the names in the series, which clarifies that three different people are included in the subject of the sentence.