In the following compounds,
(I) (II) (III) (IV)
the decreasing order of acidic strength is

Options

A. `III gt IV gtI gtII`
B. `I gt IV gtIIIgt II`
C. `II gt I gt III gt IV`
D. `IV gt IIIgt I gt II`

Answer

D

Explanation

Electron-withdrawing effect of a group increases the adidity of pheonls and electron-releasing group has the opposite effect.
In (II),there is a `(+I)`effect of `-CH_(3)` groups. [decreases acidity]
In `(III)`, there is a `(-I)` effect of `-NO_(2)` group [increase aidity]
In `(IV)`, there is `(-I)` and `(-R)` effect of `-NO_(2)` group. [strongly increases acidity]