Which molecule has the shortest bond between carbon atoms?

A.     ${{\text{C}}_{\text{2}}}{{\text{H}}_{\text{6}}}$

B.     ${{\text{C}}_{\text{2}}}{{\text{H}}_{\text{4}}}$

C.     ${{\text{C}}_{\text{2}}}{{\text{H}}_{\text{2}}}$

D.     ${{\text{C}}_{\text{2}}}{{\text{H}}_{\text{4}}}{\text{C}}{{\text{l}}_{\text{2}}}$

C