Answer
Double membrane that separates the nucleus from the cytoplasm is from Nuclear Envelope
Explanation
The nuclear envelope consists of a pair of lipid bilayer membranes, an inner nuclear membrane, and an outer nuclear membrane. The area connecting the membranes is termed as the perinuclear space. The double layer that separate the content of the nucleus and cytoplasm is called nuclear envelope. This envelope is riddled with holes called nuclear pores that allow specific types and sizes of molecules to pass between the nucleus and the cytoplasm.
