Laspeyres Index was created by the German economist Étienne Laspeyres. The technique designed by Laspeyres uses base-period weights. It consists of the information about the price and quantity of products in different periods. The weighting scheme makes it a better tool than simple indexes. By using the Laspeyres index, it is possible to make a comparison of today’s price and quantity between the price and quantity of items altogether for a base period. The Laspeyres price index is also known as the average of weighted relative prices since it is a composite index number of prices formed by the weighted sum method. The index is found by the ratio of the sum of prices in the current period to the sum of the prices in the base period, these sums are weighted by the respective quantities of the base period. In this case, the weights which are used are the quantities of each commodity in the base period. So, it measures the relative price change of the commodities when the respective quantities are considered unchanged. The correct answer is B.