Which choice represents the simplified form of the expression below and the values of x for which it is defined?
√7x^3 divide by √x
A.x√2x when x>0
B.x√7 when x<0
C.x√7 when x>1
D.x√7 when x>0
√7x^3 divide by √x
A.x√2x when x>0
B.x√7 when x<0
C.x√7 when x>1
D.x√7 when x>0