The simplified form of (x¹⁵ y²¹ z³⁰) 1/3 is.
a. (x⁴⁵ y⁶³ z⁹⁰)
b. (x⁵ y⁷ z ¹⁰)
c. (x¹² y¹⁸ z²⁷)
d. (x¹⁵/³ y²¹/³ z³⁰/³)​