In the organic compound ${\mathrm{CH}}_2=\mathrm{CH}–{\mathrm{CH}}_2–{\mathrm{CH}}_2–\mathrm{C}\equiv \mathrm{CH}$, the pair of hybridised orbitals involved in the formation of ${\mathrm{C}}_2–{\mathrm{C}}_3$ bond is:
 

In the Lassaigne’s test for nitrogen in an organic compound, the Prussian blue colour is obtained due to the formation of

The reaction: ${\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{I}+\mathrm{KOH}\left(\mathrm{aq}\right)\to {\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{OH}+\mathrm{KI}$ is classified as: