Volatile Organic Compounds (VOCs) are known to:

Volatile Organic Compounds (VOCs) are organic chemicals that can easily evaporate at room temperature. This property results in their widespread presence in indoor environments, often emitted from various sources such as paints, cleaning supplies, and building materials. Importantly, many VOCs can contribute to a range of health issues, including respiratory problems, headaches, and other acute and chronic health effects.

The correct understanding of VOCs acknowledges the potential for these compounds to negatively impact indoor air quality, making option B an accurate representation of their characteristics. While some VOCs exist in low concentrations and may have limited health effects, many are known to be harmful, especially in poorly ventilated spaces where they can accumulate.

In this context, the other options do not capture the realities of VOCs adequately. While enhancing indoor air quality or being harmless in indoor settings may apply to extremely specific and low-risk situations, they do not reflect the broader public health concerns associated with VOCs in most indoor environments. Similarly, the misconception that VOCs only affect outdoor air quality overlooks their significant contributions to indoor air pollution and associated health risks.