The correct answer is C. Toner cartridges.
Toner cartridges are the easiest component to environmentally recycle because they are made of a variety of materials that can be easily recycled, including plastic, metal, and paper. Additionally, toner cartridges are often collected by businesses and organizations for recycling, which makes it easy for consumers to recycle them.
Motherboards are made of a variety of materials, including plastic, metal, and ceramic. Some of these materials can be recycled, but others cannot. Additionally, motherboards are often difficult to disassemble, which makes it difficult to recycle them.
CMOS batteries are small, round batteries that are used to power the BIOS on a computer. CMOS batteries are made of a variety of materials, including lithium and nickel. These materials can be recycled, but they are often difficult to recycle because they are small and difficult to disassemble.
Cathode ray tubes (CRTs) are the large, glass tubes that are used in cathode ray tube (CRT) monitors and televisions. CRTs contain a variety of materials, including lead, barium, and arsenic. These materials are hazardous and must be recycled properly.
Therefore, the easiest component to environmentally recycle is C. Toner cartridges.