The accurate choice, Option 2, is silicon dioxide. Explanation: Clocks utilize quartz crystals, which consist of silicon dioxide. Quartz watches operate on batteries, with their mechanisms regulated by a small quartz crystal. Quartz, the most prevalent form of crystalline silica, is the second most abundant mineral on Earth's surface. Therefore, quartz crystals commonly found in devices like quartz clocks are essentially composed of silicon dioxide. Additionally, quartz crystals exhibit piezoelectric properties, generating a minute electric voltage when compressed, and vice versa. When subjected to an applied voltage, the quartz crystal oscillates at a precise frequency, typically 32768 times per second. This frequency is utilized by the electronic circuitry, powered by the battery, to produce regular electric pulses, indicating time on the LCD display or controlling the movement of hands on the clock face.