Cross-sectional returns studies contend that:（）
A. all securities should have equal risk-adjusted returns because security prices should reflect all public information that would influence the security’s risk.
B. all securities should have equal risk-adjusted returns because security prices should not reflect all public information that would influence the security’s risk.
C. securities should not have equal risk-adjusted returns because security prices should not reflect all public information that would influence the security’s risk.
