The correct answer is: B. stand-alone risk
Stand-alone risk is the risk of a project or investment taken on by itself, without considering any other investments or projects. It is the risk that is inherent to the project or investment, and cannot be diversified away.
Expected risk is the average of the possible outcomes of a project or investment, weighted by their probabilities. It is a measure of the potential for loss or gain from the project or investment.
Variable risk is the volatility of the returns from a project or investment. It is a measure of how much the returns from the project or investment are likely to vary over time.
Returning risk is the risk that the returns from a project or investment will not be as high as expected. It is a measure of the potential for loss from the project or investment.
In conclusion, stand-alone risk is the risk of a project or investment taken on by itself, without considering any other investments or projects. It is the risk that is inherent to the project or investment, and cannot be diversified away.