
The question involves identifying which compounds can be oxidized by periodic acid (\(HIO_4\)). Periodic acid is known to cleave vicinal diols and α-dicarbonyl compounds.
Let's analyze each option:
Based on this analysis, compounds 1, 2, and 4 are oxidized by \(HIO_4\). Therefore, the correct answer is Option: 1, 2 and 4.