What is the distinguishing characteristic of spurges?

The correct answer highlights the distinguishing characteristic of spurges, which is their milky, acrid, and irritating sap. This sap is a key identifier for spurges and serves as a defense mechanism against herbivores. When the sap is exposed to air, it can also create a sticky residue that can further deter feeding. Additionally, this milky sap can cause skin irritation in humans, which is an important aspect to consider for those handling the plant during maintenance or removal.

Recognizing this characteristic is crucial for anyone involved in pest control or landscape management, as it not only helps in correctly identifying spurges but also in understanding how to handle them safely to avoid any adverse effects. The other options, while they may pertain to various plants, do not specifically define what makes spurges unique. Understanding this key trait provides practical knowledge for managing spurges in ornamental and turf settings effectively.