Butanedioic acid is present in amber, algae, lichens, sugar cane and beets. It can be prepared in two stages from $\text{BrCH}_2\text{CH}_2\text{Br}$. $\text{BrCH}_2\text{CH}_2\text{Br} \xrightarrow{\text{step 1}} X \xrightarrow{\text{step 2}} \text{HO}_2\text{CCH}_2\text{CH}_2\text{CO}_2\text{H}$. Which reagents could be used to carry out this synthesis?
- Astep 1: $\text{HCN}(g)$; step 2: $\text{HCl}(aq)$
- Bstep 1: $\text{HCO}_2\text{Na}(aq)$; step 2: $\text{HCl}(aq)$
- Cstep 1: $\text{KCN}(aq/\text{alcoholic})$; step 2: $\text{H}_2\text{SO}_4(aq)$
- Dstep 1: $\text{NaOH}(aq)$; step 2: $\text{K}_2\text{Cr}_2\text{O}_7/\text{H}_2\text{SO}_4(aq)$