One key function of nuclear pore is to
A. Allow cells to communicate with one another
B. Aid in the production of new nuclei
C. Allow molecules such as proteins to move into and out of the nucleus
D. For connections between different organelles

Hint: The nuclear envelope has tiny holes known as nuclear pores. These pores provide a passage for transport of molecules between the nucleus and cytoplasm. Nuclear pore has several subunits which together form a channel.

Complete answer:
Nuclear pores are tiny holes present in the nuclear envelope. They provide access to the nucleus and also provide a passage for the transport of the molecules. They are aqueous in nature and are composed of multiple proteins called nucleoporins. The nuclear pores are permeable to small molecules. Nuclear pore complex has four major components:
-Scaffold- include the pores and is a stack of three rings, namely, cytoplasmic ring, nucleocytoplasmic ring and a central ring of thick spokes.
-Transporter- it is proteinaceous and carries our transport of proteins and RNA. The spokes of central ring are attached to the transporter
-Short filaments- they are thick and attach to the cytoplasmic side of the pore.
-Basket- attach to the nucleocytoplasmic side of the pore and also play an important role in RNA export.

Function of nuclear pore includes; movement of small molecules and ions to freely pass onto or out of the nucleus; allow necessary proteins to enter the nucleus from the cytoplasm.

Hence, the correct answer is option (C).

Note: Nuclear pores are embedded in a nuclear envelope or membrane, which is made up of two lipid bilayers in eukaryotes. It consists of an inner nuclear membrane and outer nuclear membrane. Prokaryotes do not have nuclear membrane and thereby do not have nuclear pore complex.