निम्नलिखित में से कौन सा सूखे कचरे (Dry garbage) के अंतर्गत वर्गीकृत नहीं किया जाता 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)?