निम्नलिखित में से कौन-सा पर्यावरण सम्मेलन/प्रोटोकॉल उसके उद्देश्य के साथ सही सुमेलित 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)?