Given below is the electron dot structure of [[1]].

Ethyne has the chemical formula ${\mathrm{C}}_2{\mathrm{H}}_2$. Carbon has four valance electrons and hydrogen has one electron in valance shell. Thus total number of valance electron becomes 10. Thus five covalent bonds must be present. three bonds are formed in between four atoms.

$\mathrm{H}-\mathrm{C}-\mathrm{C}-\mathrm{H}$

The remaining bonds is formed as multiple bonds between carbons by sharing their remaining two valance electrons.

$\mathrm{H}-\mathrm{C}\equiv \mathrm{C}-\mathrm{H}$

Thus the dot structure can be represented as in figure.

Hence, Ethyne is correct answer.