Just after entering a cell, a virus

A) begins assembling more viruses.
B) removes its envelope.
C) loses its protein capsid and the viral genome is exposed.
D) immediately integrates its nucleic acid genome into the host chromosomes.
E) begins its cycle, which always results in the death of the animal cell.

After entering a cell, a virus loses its protein capsid, which exposes its viral genome. This is the first step in initiating the viral replication cycle. The other options are not correct because a virus cannot begin assembling more viruses or integrate its nucleic acid genome into the host chromosomes immediately after entering the cell. Additionally, not all viruses result in the death of the animal cell during their cycle.