A hydrocarbon (A) containing 90% carbon and having V.D. 20 reacts with dil. `H_2 SO_4` in the presence of `H_2 SO_4` to give (B). Compound (B) is reduced by `LiAIH_4` to (C) which on heating with `H_2 SO_4` gives (D). Compound (A) can be converted into (D) directly by hydrogenation in the presence of deactivated palladium-calcium carbonate catalyst. Identity the compounds (A) to (D) and explain the reactions involved.

Explanation

Structure for acid is