Use the Following Three Statements to Answer This Question

Multiple Choice

Use the following three statements to answer this question:
I.Beta is constant over time.
II.Empirically beta is never negative.
III.Negative beta implies a negative standard deviation.

A) I, II and III are correct.
B) I, II and III are incorrect.
C) I is correct, II and III are incorrect.
D) I, II are incorrect, III is correct.