Which of these exoressions is in the simplified form

Question

A.  √1/2x+√1/2z        B.  √125x-x2.     C.  x2-3x√y/√3    D.  a3√4-b3√2/2

Answer 1

My guess is B, (√125x-x²), because:

A results in a square root in the denominator;

C has a square root in the denominator;

In D, the square root of 4 can be simplified to 2;

B contains no division by a square root, although √125 can be written 5√5.