Which of the following is true about bonds?

The bond rating being changed from BBB+ to B would result in a lower required yield

The primary advantage to municipal bonds is that interest income received is not taxed by the federal government

Interest from mortgage bonds are not taxed by the Federal Government.

Spread to treasuries measures the difference between the coupon rate paid by a bond and the coupon rate paid by risk free security with the comparable maturity

Only bonds issued in the primary market are subject to prepayment risk