The correct answer is (a) 100 mg.
A carat is a unit of mass equal to 200 milligrams (mg) or 0.2 grams (g). It is used to measure the weight of gemstones, including diamonds. The word “carat” comes from the Greek word “keration,” which means “carob seed.” Carob seeds were once used as a unit of weight, and they are about the same size as a diamond of one carat.
The carat is divided into 100 points, so a diamond that weighs 0.25 carats is also said to weigh 25 points. The carat weight of a diamond is one of the four Cs of diamond grading, along with cut, color, and clarity.
The carat weight of a diamond is important because it affects the price. Larger diamonds are more rare and expensive than smaller diamonds. However, the price of a diamond is not determined solely by its carat weight. Other factors, such as the cut, color, and clarity of the diamond, also affect its value.