Which of the Following Characteristics Distinguishes the Coccolithoviruses from the Chloroviruses

Which of the following characteristics distinguishes the coccolithoviruses from the chloroviruses, which are both member of the phycodnavirus family?

A) Only the coccolithoviruses have a virion with an internal envelope.
B) Only the coccolithoviruses are predicted to encode over 300 proteins.
C) Only the coccolithoviruses replicate entirely in the nucleus of the host cell.
D) Only the coccolithoviruses encode their own DNA polymerase.
E) Only the coccolithoviruses encode their own RNA polymerase.