__ Substances arranged in the sequence: oxide - base - salt , are in a row Answer 1. H_(2)O- LiOH- KHCO_(3) 2. P_(2)05- ZnSO_(4) Ba(OH)_(2) 3. OF_(2)- NaOH- Pbl_(2) 4. CaO- H_(2)CO_(3) -NaOH

The correct answer is option 4: .In this sequence, the substances are arranged in the order of oxide, acid, and base. 1. is calcium oxide, which is an oxide.2. is carbonic acid, which is an acid.3. is sodium hydroxide, which is a base.Therefore, the correct answer is option 4.