We would use "ellos" as the plural subject pronoun to talk about Felipe and Arianna (they).
The plural subject pronoun you would use to talk about Felipe and Arianna (they) is "ellos."
The plural subject pronoun you would use to talk about Felipe and Arianna is "ellos." To find the correct answer, you need to know that in Spanish, subject pronouns change based on the gender and number of the subject. Since Felipe and Arianna are both masculine, the plural subject pronoun for a group of males is "ellos."
