Answer
$\emptyset$
Work Step by Step
RECALL:
(1) $\cap$ represents intersection of sets, which is the set that contains the elements that are common to the sets involved.
(2) $\emptyset$ represents the empty set, which has no elements.
Since $\emptyset$ is empty, then the two set have no common elements.
Thus,
$\color{blue}{D \cap \emptyset = \emptyset}$
