Suppose A and B are n × n matrices with real entries. Which of the follow are TRUE?
I. The trace of A^2 is nonnegative.
II. If A^2 = A, then the trace of A is nonnegative.
III. The trace of AB is the product of the traces of A and B.
(A)II only (B)III only (C)I and II only (D)II and III only
A