In order to get the benefit of minimising risk in a portfolio, we need to: a. Add assets to our portfolio that move in the same direction to the assets in our portfolio. b. Add assets to our portfolio that have a correlation of +1 to the assets in our portfolio. c. Add assets to our portfolio that have a correlation of less than 1 to the assets in our portfolio. d. Add assets to our portfolio that have similar unsystematic risk to the assets in our portfolio.