An Insulator.
Insulators prevent flow of electric current. Example is wood, clay.
I would believe the answer to this question is D. According to the concept of the tragedy of the commons, shared resources are used by more than one organism. Due to the large consumption of shared resources they start to be fewer and fewer in number and over time if we are not careful they will be depleted.
I believe it is an ion with a 1+ charge. If you remove an electron from an atom it will have a positive charge. But if you add electrons it will be a negative charge. Hope I helped!
