Guideline value for drinking water is: September 2007
**Core Concept**
The guideline value for drinking water refers to the maximum acceptable level of contaminants in water that is considered safe for human consumption. This value is typically set by regulatory agencies to protect public health.
**Why the Correct Answer is Right**
The World Health Organization (WHO) has established a guideline value for various contaminants in drinking water. In 2007, the WHO revised its guidelines, recommending a maximum allowable level of 0.1 mg/L for certain contaminants. This value ensures that drinking water is free from excessive levels of harmful substances, safeguarding human health.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it does not specify a known contaminant or a relevant guideline value.
**Option B:** This option is incorrect as it does not align with the 2007 WHO guidelines for drinking water quality.
**Option C:** This option is incorrect as it is not a recognized guideline value for drinking water.
**Clinical Pearl / High-Yield Fact**
It is essential to note that guideline values can vary depending on the specific contaminant and the regulatory agency. Students should be familiar with the WHO guidelines for drinking water quality and the recommended maximum allowable levels for various contaminants.
**Correct Answer:** C.