The correct answer is: C. less than original price.
A positive minimum risk portfolio of any security shows that the market security sold at a price less than the original price. This is because the portfolio is constructed to minimize risk, and this can be done by selling the security at a lower price.
Option A is incorrect because the market security is not sold at the original price. Option B is incorrect because the market security is not sold at the sum of the stocks. Option D is incorrect because the market security is not sold at a price greater than the original price.