49 Related to a bond rating change, substantive price changes tend to occur

(a) from six months before to six months after.

(b) within three months after the announcement.

(c) one week before.

(d) from eighteen to seven months before.

50 Evidence supports that the bond market is

(a) semi-strong efficient.

(b) weak form efficient.

(c) unrelated to the changes in interest rates

(d) strong form efficient.