Which of the Following Is a Type I Statistical Error

Multiple Choice

Which of the following is a Type I statistical error?

A) Saying that an independent variable had no effect when in fact it did
B) Saying that an independent variable had an effect when in fact it did not
C) Saying that an independent variable had a weak effect when in fact it had a strong effect
D) Identifying one independent variable as affecting the dependent variable when in fact a different independent variable had the effect