Correct option is C
In the process of creating lab-grown diamonds (LGDs), graphite (a form of carbon) is typically used as the carbon source. The process involves subjecting graphite to high pressure and temperature (HPHT process) or using chemical vapor deposition (CVD), where a diamond seed crystal is placed in a chamber, and carbon atoms are deposited on it to grow the diamond. The seed is made of a small piece of natural diamond or a pre-existing synthetic diamond, but the carbon source is commonly graphite.
