Which-of the following statements used to describe the Student’ s t-distribution is least accurate The Student’s t-distribution:（）

单项选择题Which of the following statements best explains how automatic stabilizers work Even without a change in fiscal policy, automatic stabilizers tend to promote:（）

A. a budget surplus during a recession and a budget deficit during an inflationary expansion.
B. a budget deficit during a recession but do not promote a budget surplus during an inflationary expansion.
C. a budget deficit during a recession and a budget surplus during an inflationary expansion.

单项选择题Which of the following is NOT a reason bond market indexes are more difficult to create than stock market indexes（）

A. Bond deviations tend to be relatively constant.
B. There is a lack of continuous trade data available for bonds.
C. The universe of bonds is always changing due to new issues, retired bonds, sinking funds and calls.