Given below are two statements:

Statement I: IUPAC name of Compound A is 4-chloro-1,3-dinitrobenzene.

Statement II: IUPAC name of Compound B is 4-ethyl-2-methylaniline. In the light of the above statements, choose the most appropriate answer from the options given below:

Compound A consists of a benzene ring substituted with one chlorine ($$\text{--Cl}$$) atom and two nitro ($$\text{--NO}_2$$) groups. Since both chloro and nitro groups are treated purely as prefixes with equal priority in IUPAC nomenclature, the numbering of the ring is determined by the lowest locant rule:

• Path 1 (Correct): Numbering starts at the carbon attached to the chlorine atom and proceeds towards the nitro groups. This gives the locant set $$(1, 2, 4)$$.

  Following alphabetical order (chloro before nitro), the correct IUPAC name is 1-chloro-2,4-dinitrobenzene.

• Path 2 (Incorrect): If numbered as given in the statement, the locant set would be $$(1, 3, 4)$$, resulting in 4-chloro-1,3-dinitrobenzene. Since $$(1, 2, 4)$$ is lower than $$(1, 3, 4)$$, this path violates the lowest locant rule.

Therefore, Statement I is incorrect.

Compound B contains an amino group ($$\text{--NH}_2$$), an ethyl group ($$\text{--CH}_2\text{CH}_3$$), and a methyl group ($$\text{--CH}_3$$) attached to a benzene ring.

1. The principal functional group is the amino group ($$\text{--NH}_2$$), which gives the parent ring the name aniline and automatically assigns position $$1$$ to the carbon bearing the amino group.
2. Numbering proceeds around the ring to give the lowest possible locants to the remaining substituents (methyl and ethyl groups), resulting in positions $$2$$ and $$4$$.
3. Listing the substituents alphabetically (ethyl before methyl) gives the name 4-ethyl-2-methylaniline.

Therefore, Statement II is correct.

Conclusion:

Statement I is incorrect because it violates the lowest locant rule, while Statement II correctly applies principal functional group priority and alphabetical substituent ordering.

Answer: Option D — Statement I is incorrect but Statement II is correct.