A mean variance optimal portfolio that has a negative weight in the risk-free asset is a levered portfolio because

A. the portfolio borrowed against that asset

B. a risk-free asset means leverage is a part of every portfolio

C. portfolios along the efficient frontier combine the risk-free asset and the market (tangency) portfolio in equal proportions

D. the risk-free asset is the intercept on the vertical axis, representing zero volatility on the efficient frontier