# If the $2^{nd},\; 5^{th}$ and $9^{th}$ terms of a non-constant A.P. are in G.P., then the common ratio of this G.P. is :
( A ) $\frac{4}{3}$
( B ) $1$
( C ) $\frac{8}{5}$
( D ) $\frac{7}{4}$