Foreign direct investment in plant, equipment, or real estate is: (a) Always a more stable source of funds than funds acquired through short-term instruments such as commercial paper, Treasury bills, or bank deposits. (b) Generally, but not necessarily, a more stable than funds acquired though the sale of short-term instruments. (c) Hard for a foreign investor to liquidate: Once the hard assets are in place they cannot be removed easily. (d) Answers (a) and (c).