(A) $$\mathrm z+\frac1{2!}\frac1{\mathrm z}+\frac1{4!}\frac1{\mathrm z^3}+\frac1{6!}\frac1{\mathrm z^5}+......$$
(B) $$\mathrm z-\frac1{2!}\frac1{\mathrm z}+\frac1{4!}\frac1{\mathrm z^3}-\frac1{6!}\frac1{\mathrm z^5}+......$$
(C) $$\mathrm z-\frac12\frac1{\mathrm z}+\frac14\frac1{\mathrm z^3}-\frac16\frac1{\mathrm z^5}+......$$