When a substance A reacts with water it produces a combustible gas B and a solution of a substance C — AITS & Test Series Chemistry Question

Question

When a substance A reacts with water it produces a combustible gas B and a solution of a substance C in water. When another substance D reacts with this solution of C, it also produces the same gas B even on reaction with dilute sulphuric acid at room temperature. A imparts a deep golden yellow colour to a smokeless flame of Bunsen burner. A, B, C and D respectively are (A) Na, H2, NaOH and Zn (B) K, H2, KOH and Al (C) Ca, H2, Ca(OH)2 and Sn (D) CaC2, C2H2, Ca(OH)2 and Fe