a One Direction

b 5 Seconds of Summer

c Black Eyed Peas

d Daft Punk

a Lady Gaga

b Rihanna

c Beyoncé

d Britney Spears

a Jason Derulo

b Chris Brown

c Trey Songz

d Usher

a Selena Gomez

b Shy'm

c Miley Cyrus

d Katy Perry

a Harry Styles

b Niall Horan

c Liam Payne

d Zayn Malik

a Vanessa Hudgens

b Arianna Grande

c Iggy Azalea

d Beyoncé

a Cody Simpsons

b Louis Tomlinson

c David Carreira

d Justin Bieber