the

portion of the investment opportunity set that represents the highest standard

deviations.

the

set of portfolios that have zero standard deviation.

the

portion of the investment opportunity set that lies above the global minimum

variance portfolio.

both

the portion of the investment opportunity set that lies above the global

minimum variance portfolio and the portion of the investment opportunity set

that represents the highest standard deviations.

the

portion of the investment opportunity set which includes the portfolios with

the lowest standard deviation.