निम्नलिखित में से कौन सा ठोस अपशिष्ट प्रबंधन पदानुक्रम का एक उद्देश्य या यथार्थवादी स्तंभ नहीं है?

Prolonged exposure to extreme cold temperatures may result in tissue damage known as frostbite, which is categorized as a:

In the context of ecosystem energy dynamics, which of the following expressions correctly defines Net Primary Productivity (NPP)?