Which of the following is not a polynomial

Question

(A) 2/3x+1  (B) 2-x² +√3x

  

(C) 1/x-1 .    (D) x³

Answer 1

It's not possible to rule out A because, according to PEMDAS, this says two thirds of x, then add 1; B is also a polynomial if the coefficient of x is just 'square root of 3' in the last terms; C is NOT a polynomial regardless of whether denominator is just x, or it's 9x-1); therefore, in spite of some ambiguities, the answer has to be C.