Identify (A) based on the following facts:
a. (A) redues `HgCI_(2)` solution to white ppt changing to grey
b.(A) turn `FeCI_(3)` yellow coloured solution to green
c. (A) gives while ppt `NaOH` soluble in excess of `NaOH`
d. (A) gives yellow dirty ppt ,on passing `H_(2)S` gas in yellow ammonium salphide `(YAS)`
e. (A) gives chromyl chloride test