18. Given an ordered quadruple of real numbers $(a, b, c, d)$, where $a, b, c, d \in \{0,1,2,3\}$, and $a, b, c, d$ can be the same. Then there are ( ) such quadruples of real numbers such that $a d - b c$ is odd. For example, the quadruple $(0,3,1,1)$, $0 \times 1 - 3 \times 1 = -3$ is odd.
(A) 48
(B) 64
(C) 96
(D) 128
(E) 192
18. C.

To make $ad-bc$ an odd number, we only need to consider that the parity of $ad$ and $bc$ are different. In this case,
$$
N=(2 \times 4+2 \times 2) \times 2 \times 2 \times 2=96 \text {. }
$$