The number of activating and deactivating groups among the following are respectively: $-OCH_2CH_3, -COCH_3, -NHCOCH_3, -COOCH_3, -SO_3H$

With respect to the compounds $I-V$,choose the correct statement$(s)$.
$(A)$ The acidity of compound $I$ is due to delocalization in the conjugate base.
$(B)$ The conjugate base of compound $IV$ is aromatic.
$(C)$ Compound $II$ becomes more acidic,when it has a $-NO_2$ substituent.
$(D)$ The acidity of compounds follows the order $IV > V > I > II > III$.

Which group exhibits the maximum hyperconjugation effect?

Which of the following groups as $X$ will decrease the $pKa$ value of the given compound?

Which of the following is the most stable carbanion?

Find the compound that has the maximum enol content.