1- In carboxylic acid derivatives, a key step in the Rx of the carbonyl group is:
a- The addition of a nucleophile that generates a tetrahedral intermediate
b- An aldehyde and ketone are presented as a good leaving group
c- The use of a steric hindrance in the reaction
d- The addition of a limiting reagent

2- It is an azo compound:
a- chondroitin sulfate
b- ethylazomethane
c- p-hydroxyazobenzene
d- m-hydroxy acetophenone