A thin prism $P_1$ with angle $4^o$ made from glass of refractive index 1.54 is combined with another thin prism $P_2$ made from glass of refractive index 1.72 to produce dispersion without deviation. The angle of the prism $P_2$ is

• A

  $5.{33}^o$

• B

  $4^o$

• C

  $3^o$

• D

  $2.6^o$