Which of the following cannot be used as an antiseptic?

Options

A. Alcohol
B. Carbolic acid
C. Boric acid
D. Hydrochloric acid

Answer

To determine which of the following cannot be used as an antiseptic, we will analyze each option provided:

1. **Alcohol**: Alcohol is commonly used as an antiseptic. It is effective in killing bacteria and is often used for cleaning wounds and sanitizing skin.

2. **Carbolic Acid**: Also known as phenol, carbolic acid is used as an antiseptic. It has antibacterial properties and is used in some medical applications.

3. **Boric Acid**: Boric acid is another substance that can be used as an antiseptic. It is often used to treat minor cuts and burns and can help prevent infections.

4. **Hydrochloric Acid**: Hydrochloric acid is a strong acid and is not used as an antiseptic. It can cause severe burns and damage to the skin and tissues, making it unsuitable for antiseptic use.

Based on this analysis, the substance that cannot be used as an antiseptic is **Hydrochloric Acid**.

### Final Answer:
**Hydrochloric Acid (Option D)** cannot be used as an antiseptic.

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