Question: Who was the featured singer in Katy Perry's song "E.T."?
Sentence (from "Katy Perry discography"): She currently holds the record for most 5-million-selling singles in the United States, with six of her singles selling over 5 million (in order of release date: "Hot n Cold", "California Gurls", "Firework", "E.T.", "Roar", and "Dark Horse").
Relevant evidence: Yes