Which of the following reactions involve benzyne intermediate?

Which of the following reactions involve free radical as intermediate ?

Which of the following reactions involve carbanion enolalte as reactive intermediate?

in which of the following reaction carbene is intermediate

In which of the following reaction formation of reaction intermediate does not take place?

In which of the following reaction formation of reaction intermediate does not take place?

In which of the following reactions, the intermediate species acyl nitrene (R-overset(O)overset(||)(C)-ddot(N: )) and intermediate compound alkyl isocyanate (R - N = C = O) are involved ?