Find out number of reactions those proceed with retention of the configuration.

 

In the reaction

The reagent required for the following two step transformation are

The major product of the following reaction is:

The major product of the following reaction is:

The increasing order of reactivity of the following compounds towards reaction with alkyl halides directly is:

$\left(i\right)$

$\left(ii\right)$

$\left(iii\right)$

$\left(iv\right)$

In the reaction given below what will be the major product at the end :

The major product of the following reaction is: