Explanation:

Laspeyres formula is a method used for calculating price indexes. It is named after its creator, Etienne Laspeyres. This formula is widely used in economics, finance, and accounting for calculating the cost of living index, inflation rate, and other important economic indicators.

Factor Reversal Test:

The factor reversal test is a crucial property of a price index formula. It states that if the price index is multiplied by a factor, the resulting index should be the reciprocal of the index obtained by dividing each price by the same factor. Laspeyres formula does not obey this test, which means that it is not a reliable method for calculating price indexes.

Time Reversal Test:

The time reversal test is another important property of a price index formula. It states that if the price index is calculated for two periods in time, and the two periods are reversed, the resulting index should be the reciprocal of the original index. Laspeyres formula does not obey this test, which means that it is not a reliable method for calculating price indexes.

Circular Test:

The circular test is a property of a price index formula that ensures that the index remains constant when the prices are multiplied by a constant factor. Laspeyres formula does not obey this test, which means that it is not a reliable method for calculating price indexes.

Conclusion:

In conclusion, Laspeyres formula is not a reliable method for calculating price indexes because it does not obey the factor reversal test, time reversal test, and circular test. It is important to use a reliable method for calculating price indexes to accurately measure inflation and other important economic indicators.

It also doesn't satisfy factor reversal and circular test so answer should be D.