If $|z_1|=|z_2|=|z_3|=$ $\large|\frac{1}{z_1}+\frac{1}{z_2}+\frac{1}{z_3}|$$=1$, then $|z_1+z_2+z_3|$ = ?

Question

$\begin{array}{1 1}(A) \;1\\(B)\;0\\(C)\;3 \\(D)\;4 \end{array}$