The solid laboratory reagent A gives the following reactions:
I. It imparts green colour to the flame.
II. Its solution does not give a precipitate on passing `H_(2)S.`
III. When it is heated with solid `K_(2)Cr_(2)O_(7)` and concentrated `H_(2)SO_(4)` a red gas is evolved. When this gas is passed into aqueous solution of `NaOH` it turns yellow: Identify A.
A. `PbCI_(2)`
B. `BaCI_(2)`
C. `NaCI`
D. None of these