What is the function of the CMOS battery?

The function of the CMOS battery is to store boot configuration data, which is indeed the correct rationale for this choice. The CMOS (Complementary Metal-Oxide-Semiconductor) battery is responsible for maintaining the BIOS settings and system clock when the computer is powered off. This includes critical settings such as the system time, date, boot order, and hardware configuration. When the computer is powered down, the CMOS battery ensures that these settings are retained, allowing the system to boot up correctly with the intended configurations each time it is turned on.

In contrast, the other options refer to functions that are not associated with the CMOS battery. The motherboard itself requires power to operate, which is provided by the main power supply rather than the CMOS battery. Regulating system temperature is typically handled by fans and thermal sensors, not the CMOS battery. Enhancing system graphics is the function of the graphics card, which operates independently of the CMOS battery's role. Thus, the correct answer highlights the specific and critical task of the CMOS battery in maintaining system settings for proper startup and operation.