When an Importin α/β Complex Carries a Protein Destined to Move

Multiple Choice

When an importin α/β complex carries a protein destined to move into the nucleus, what does it bind to when it comes to the outer surface of the nucleus near the nuclear pore complex?

A) the torus
B) the outer ring of the nuclear pore complex
C) the inner ring of the nuclear pore complex
D) cytoplasmic filaments that extend from the outer ring of the nuclear pore complex
E) the transporter