Generally speaking, a test of the efficient market hypothesis consists of

A$.$

testing a joint hypothesis including $1)$ that markets are efficient, and $2)$ that the model chosen for risk is correct.

B$.$

estimating time series regressions without testing any hypothesis on pricing errors.

C$.$

testing if expected asset returns are equal to zero.

D$.$

testing the hypothesis that markets are efficient, regardless of the model chosen for risk.