Question: Nucleoplasmin is a nuclear protein. This protein was divided into two segments and linked to the same large cytoplasmic protein, generating two fusion proteins. After injecting these fusion proteins into a cell, one of them protein was found in the nucleus and the other in the cytoplasm. Which of the following conclusions can be drawn from these results? (2 points)

A) One of the fusion proteins entered the nucleus by passive transport.
B) Nucleoplasmin does not have a nuclear localization signal.
C) The cytoplasmic protein contains a nuclear localization signal.
D) Only one of the two fusion proteins possesses a nuclear localization signal.