An Ellingham diagram provides information about :

Among statements (a) - (d), the correct ones are
(a) Lime stone is decomposed to CaO during the extraction of iron from its oxides.
(b) In the extraction of silver, silver is extracted as an anionic complex.
(c) Nickel is purified by Mond’s process.
(d) Zr and Ti are purified by Van Arkel method.

Cast iron is used for the manufacture of :

According to the following diagram, A reduces BO₂ when the temperature is :