Which of the following is an example of synthetic oils?

Synthetic oils are artificially created substances designed to provide better performance and stability under varying conditions compared to natural oils. The correct choice, which includes polyglycols and silicones, highlights two types of synthetic oils that are engineered through chemical processes to enhance their properties for lubrication, heat resistance, and longevity.

Polyglycols, for instance, are made by polymerizing glycols, creating a smooth and stable lubricant suitable for various applications, especially in extreme temperatures. Silicones, on the other hand, are synthetic compounds that have unique properties like moisture resistance and stability at high temperatures, which can be advantageous in many engineering applications.

The other options represent natural or non-synthetic sources of oils. Animal fats, mineral oils, and vegetable oils are derived from biological sources and undergo minimal processing compared to synthetic oils, which are specifically formulated to meet precise performance criteria. This distinct manufacturing process is why polyglycols and silicones are categorized as synthetic oils, making this the correct choice.