Acidic drain cleaners made of . . . . . . . . or . . . . . . . . add are powerful enough to clear heavy-duty hair, food, grease, soap scum or paper-based clogs in 15 minutes or less. A. formic, citric B. nitric, carbonic C. sulphuric, hydrochloric D. malic, lactic

The correct answer is C. sulphuric, hydrochloric.

Sulphuric acid and hydrochloric acid are both strong acids that can dissolve organic matter, such as hair, food, grease, soap scum, and paper. They are also very effective at dissolving minerals, which can be a major cause of clogs.

Formic acid and citric acid are both weak acids that are not as effective at dissolving organic matter or minerals. Carbonic acid is a weak acid that is found in carbonated beverages. It is not effective at dissolving organic matter or minerals. Malic acid and lactic acid are both weak acids that are found in fruits and vegetables. They are not effective at dissolving organic matter or minerals.

Sulphuric acid and hydrochloric acid are both available in commercial drain cleaners. They should be used with caution, as they can be dangerous if not used properly. It is important to read the label carefully and follow the instructions.