The correct answer is A. less than original price.
A negative minimum risk portfolio of any security shows that the market security sold at a price less than the original price. This is because the minimum risk portfolio is a portfolio that minimizes the risk of loss, and a security that is sold at a price less than the original price is a security that has lost value.
Option B is incorrect because a security that is sold at a price greater than the original price is a security that has gained value. Option C is incorrect because a security that is sold at a price equal to the original price is a security that has neither gained nor lost value. Option D is incorrect because a security that is sold at a price equal to the sum of its stocks is a security that has been sold at a price that is equal to the total value of its stocks.