# Which of the following represent the given mode of hybridisation $sp^2-sp^2-sp-sp$ from left to right?
$\begin{array}{1 1}(a)\;H_2C=C=C=CH_2\\(b)\; HC\equiv C-C\equiv CH\\(c)\;H_2C=CH-C\equiv N\\(d)\;\text{None of these}\end{array}$