Among the following sets,the most stable ionic species are

Given below are two statements:
Statement $I$: In $O_2N-C_6H_4-CH^+-C_6H_4-OCH_3$, the carbocation is stabilised by $+R$ effect of $-OCH_3$ group.
Statement $II$: In $O_2N-C_6H_4-CH^--C_6H_4-OCH_3$, the carbanion is stabilised by $-R$ effect of $-NO_2$ group.
In the light of the above statements, choose the correct answer from the options given below:

In which of the following compounds is the hyperconjugation effect not present?

Write the correct order of acidic strength for the following:
$(I) \ CH_3 - NO_2$
$(II) \ NO_2 - CH_2 - NO_2$
$(III) \ CH_3 - CH_2 - NO_2$
$(IV) \ (NO_2)_3CH$

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

What are the characteristics of the inductive effect?