27 question is a doubt

Q27. In an experiment for determination of refractive index of a prism by  i – $\mathrm{\delta }$ , plot, it was found that a ray incident at angle 35°, suffers a deviation of 40° and that it emerges at angle 79°. In that case which of the following is closest to the maximum possible value of the refractive index ?     [JEE(Main) 2016]

  (A) 1.5                                     (B) 1.6                                     (C) 1.7                             (D) 1.8