Correct Answer: Oxalic acid solution

Solution : The correct option is Oxalic acid solution

Oxalic acid's main applications include cleaning on bleaching, especially for the removal of rust(iron complexing agent).

Oxalic acid is an organic compound with the formula H2C2O4. It is a colourless crystalline solid that dissolves in water to give colourless solutions.

Oxalic acid is a reducing agent and its conjugate base, known as oxalate , is a chelating agent for metal cations.

Typically, oxalic acid occurs as the dihydrate. Ingestion of oxalic acid through skin contact or orally is dangerous.

Oxalic acid’s main applications include cleaning or bleaching, especially for the removal of rust, e.g. Bar Keepers Friend is an example of a household cleaner containing oxalic acid.

Final answer is Oxalic acid solution