The Confidence Index Published by Barron's Is the Ratio of the Average

The confidence index published by Barron's is the ratio of the average yield on 10 top grade corporate bonds to the

A) Average yield on 30 blue chip corporate stocks.
B) Average yield on 40 convertible corporate bonds.
C) Yield on U.S. Treasury bills.
D) Yield on the Dow Jones average of 40 bonds.
E) Yield on the Shearson Lehman Hutton Corporate Bond Index