Match the species in Column I with their types in Column II.
Let’s match the species from Column I to their correct types in Column II:
1. DDT (A): DDT (Dichlorodiphenyltrichloroethane) is a well-known pesticide, so it matches with 4. Pesticides.
2. NaClO\(_3\) (B): Sodium chlorate (NaClO\(_3\)) is commonly used as a herbicide, so it matches with 3. Herbicides.
3. Cl\(_2\) (C): Chlorine gas (Cl\(_2\)) is a disinfectant, so it matches with 2. Disinfectant.
4. PAN (D): PAN (Peroxyacetyl nitrate) is involved in the formation of photochemical smog, so it matches with 1. Photochemical smog.
Thus, the correct matching is \( \boxed{{A}} \), A → 4, B → 3, C → 2, D → 1.