question_answer

If \[{{a}^{x}}={{b}^{y}}={{c}^{z}}\]and \[\frac{b}{a}=\frac{c}{b}\], then \[\frac{2z}{x+z}\]is equal to

A)  \[\frac{y}{x}\]                    

B)         \[\frac{x}{y}\]

C)  \[\frac{x}{z}\]                  

D)         \[\frac{z}{x}\]