What is a simpler form of the radical expression?
3^sq root of 125x^21y^24
A5x^7|y^8|
B15x^21|y^24|
C15|x^21|y^24
D5x^7y^8
3^sq root of 125x^21y^24
A5x^7|y^8|
B15x^21|y^24|
C15|x^21|y^24
D5x^7y^8