A hydrocarbon (A) of molecular weight 54 reacts with an excess of `Br_2` in `CCl_4` to give a compound (B) whose molecular weight is `593%` more than that of (A). However, on catalytic hydrogenation with excess of hydrogen (A) forms (C) whose molecular weight is only `7.4%` more that that of (A). (A) reacts with `CH_3CH_2Br` in the presence of `NaNH_2` to give another hydrocarbon (D) which on ozonolyisis yields diketone (E). (E) on oxidation gives propionic acid. Give the structure of (A) to (E) with reason.

Explanation

To solve the problem step by step, we will analyze the information provided and deduce the structures of compounds A to E.

### Step 1: Identify Compound A
- **Given:** Molecular weight of A = 54.
- **Reacts with Br2 in CCl4:** This indicates that A is an unsaturated hydrocarbon (likely an alkyne or alkene).
- **Molecular weight of A:** We need to find a hydrocarbon with a molecular weight of 54.

**Possible Hydrocarbons:**
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