Which of the Following Statements About the "Basis" of Stock

Multiple Choice

Which of the following statements about the "basis" of stock index futures is true?

A) It is the difference between the futures price and the value of the actual underlying index
B) Negative basis is generally considered to foretell a declining market
C) The basis reflects market changes instantaneously, while the actual underlying index moves more slowly
D) All of the above are true