: Maximum Inductive effect $(-I)$ is exerted by the group:
A. \[-{{C}_{6}}{{H}_{5}}\]
B. \[-OC{{H}_{3}}\]
C. \[-Cl\]
D. \[-CHO\]

Hint: The cluster that has lepton retreating cluster nature shows $-I$ impact. The presence of negative parts in (an exceedingly in a very) molecule builds an electron withdrawing cluster and such a gaggle shows $-I$ impact.

Complete step-by-step answer:
First, let’s perceive that $-I$ impact and so we'll see among the choices given to us.
$-I$ is that the lepton retreating inductive impact. For that initial, we must always grasp what the inductive impact is. Inductive impact is that the development of displacement of letters of the alphabet electrons towards extremely negative atoms. This ends up in generation of $2$ polar ends one that has electric charge and different with electric charge.
This impact is distance dependent and is seen in letter of the alphabet bonds solely. Inductive impact is split into $2$ varieties lepton retreating inductive impact \[\left( -I \right)\] once the negative atoms are joined by a sequence of different atoms, commonly carbon; then its lepton retreating inductive impact. Example halogens, group groups etc. lepton cathartic inductive impact \[\left( +I \right)\] Some groups are unit less lepton retreating than gas. Such group’s are referred to as lepton cathartic groups. Once such a group area unit is hooked up with a Carbon chain; they show electrons' cathartic inductive effects. Example alkyl radical groups.
Decreasing $-I$ strength as follows:
\[N{{F}_{3}}+>NR>N{{H}_{3}}+>N{{O}_{2}}>-C\equiv N\left( cyanide\text{ }group \right)>-CHO\left( aldehyde \right)>-RC\left( =O \right)R\]
\[>-R-COOH>F>Cl>Br>I>-O-R>-OH>-C\equiv CH>-N{{H}_{2}}>CH=C{{H}_{2}}>-H\]

Thus, the proper answer is that the possibility D i.e. \[-CHO\]

Note: It should be noted that the alkyl radical group’s area unit hooked up to the atom that is a lot negative in nature that typically is that the case. Example in alcohols, alkyl is hooked up with atomic number $8$ atom whereas in organic compounds, it's hooked up with salt atoms. These atomic numbers $8$ and halides area units all a lot more negative than carbon.