निम्नलिखित में से कौन-सा जैव-भूरासायनिक चक्र अवसादी चक्र (sedimentary cycle) के रूप में वर्गीकृत 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)?