An analyst does research about relationshi
题型：单项选择题
问题：
An analyst does research about relationship between credit spreads and economic well being. In general, credit spreads on corporate bonds tend to:（）
A. tighten during both economic expansions and economic contractions.
B. widen during economic expansions and tighten during economic contractions.
C. tighten during economic expansions and widen during economic contractions.