Which of the following is true for the Kronecker product A⊗BA \otimes BA⊗B where AAA is m×mm \times mm×m and BBB is n×nn \times nn×n?
tr(A⊗B)=tr(A)⋅tr(B)\text{tr}(A \otimes B) = \text{tr}(A) \cdot \text{tr}(B)tr(A⊗B)=tr(A)⋅tr(B)
tr(A⊗B)=tr(A)+tr(B)\text{tr}(A \otimes B) = \text{tr}(A) + \text{tr}(B)tr(A⊗B)=tr(A)+tr(B)
tr(A⊗B)=tr(AB)\text{tr}(A \otimes B) = \text{tr}(AB)tr(A⊗B)=tr(AB)
The trace is not defined.