$\text{ If }x=\sum _{n=0}^{\mathrm{\infty }} a^n,y=\sum _{n=0}^{\mathrm{\infty }} b^n,z=\sum _{n=0}^{\mathrm{\infty }} c^n\text{ where }a,b,c\text{ are in A.P and }\left|a\right|<1,\left|b\right|<1,\left|c\right|<1\text{, then x,y,z are in}$

• A

  AP

• B

  Arithmetico-Geometric progression

• C

  HP

• D

  GP