Hyperconjugation involves the overlap of which of the following orbitals?

Which amongst the following is the strongest acid?

$+I$ effect is shown by:

Arrange the following compounds in increasing order of the rate of aromatic electrophilic substitution reaction:

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

Match List-$I$ with List-$II$:
| List-$I$ (Mechanism steps) | List-$II$ (Effect) |
| :--- | :--- |
| $(A)$ Aniline resonance structure | $(I)$ $-E$ effect |
| $(B)$ Electrophilic addition of $H^+$ to alkene | $(II)$ $-R$ effect |
| $(C)$ Nucleophilic addition of $CN^-$ to alkene | $(III)$ $+E$ effect |
| $(D)$ Nitrobenzene resonance structure | $(IV)$ $+R$ effect |
Choose the correct answer from the options given below: