$A$ new carbon-carbon bond formation is possible in

The number of isomeric ethers with molecular formula $C_4H_{10}O$ is:

Which of the following compounds will give a tribromo derivative upon reaction with bromine water?

Match the structures in Column-$I$ with their common names in Column-$II$ and $\text{IUPAC}$ names in Column-$III$.

Column-$I$	Column-$II$	Column-$III$
$(A) \ HO-CH_2-CH_2OH$	$(1) \ \text{sec-Butyl alcohol}$	$(i) \ \text{Ethane-1,2-diol}$
$(B) \ CH_3-CH(OH)-CH_2CH_3$	$(2) \ \text{Isopropyl alcohol}$	$(ii) \ \text{2,2-Dimethylpropan-1-ol}$
$(C) \ CH_3-CH(OH)-CH_3$	$(3) \ \text{Ethylene glycol}$	$(iii) \ \text{Butan-2-ol}$
$(D) \ (CH_3)_3C-CH_2OH$	$(4) \ \text{Neopentyl alcohol}$	$(iv) \ \text{Propan-2-ol}$

An organic compound $A$ $(C_{6}H_{6}O)$ gives a dark green coloration with ferric chloride. On treatment with $CHCl_{3}$ and $KOH$,followed by acidification,it gives compound $B$. Compound $B$ can also be obtained from compound $C$ on reaction with pyridinium chlorochromate $(PCC)$. Identify $A, B$ and $C$.

$HOOC-COOH + HO^{18}CH_2-CH_2^{18}OH \xrightarrow[H^+]{\Delta} (A)$; Product $(A)$ is: