At points P, Q and R, the values of $\frac{\mathrm{dy}}{\mathrm{dx}}\mathrm{and}\frac{{\mathrm{d}}^2\mathrm{y}}{{\mathrm{dx}}^2}$ are given by following expressions
(I) At P, $\frac{\mathrm{dy}}{\mathrm{dx}}$ = 0 and $\frac{{\mathrm{d}}^2\mathrm{y}}{{\mathrm{dx}}^2}$ =Negative
(II) At Q, $\frac{\mathrm{dy}}{\mathrm{dx}}$ = 0 and $\frac{{\mathrm{d}}^2\mathrm{y}}{{\mathrm{dx}}^2}$ =Positive
(Ill) At R, $\frac{\mathrm{dy}}{\mathrm{dx}}$ = 0 and $\frac{{\mathrm{d}}^2\mathrm{y}}{{\mathrm{dx}}^2}$ = zero

Select correct alternative :

• A

  only (I) and (II)

• B

  only (II) and (Ill)

• C

  (l).(ll)and(III)

• D

  none of these